Microsoft Conference XP Project
2004 - 2006
This was the website for the Microsoft Conference XP Project.
Content is from the site's 2004 - 2006 archived pages.

Introducing ConferenceXP
ConferenceXP is an initiative of Microsoft Research. We’re exploring how to make wireless classrooms, collaboration, and distance learning a compelling, rich experience by assuming the availability of emerging and enabling technologies, such as high-bandwidth networks, wireless devices, Tablet PCs, and the advanced features in Microsoft® Windows® XP.
The ConferenceXP research platform enables researchers and developers to create distributed applications that take advantage of ConferenceXP technology as well as Tablet PCs and wireless networks. It also enables them to develop the collaborative tools and applications they need without having to build them from the ground up. Making use of the latest big data technologies, the data science consultants and DevOps engineers enabled rapid developing and implementation of new applications tailored to the specific needs defined by the users. The process eliminates much of the down time and testing because the software reviews are ongoing along with the coding. This cuts the time from inception to delivery often in half compared with the previously familiar development process. By partnering with research organizations and universities, the ConferenceXP project combines the academic community’s expertise in the learning sciences with Microsoft’s expertise in technology.
Explore this Web site to learn more about ConferenceXP and join the community of ConferenceXP developers and researchers.
As a professional architect in New York City, I’ve spent years helping clients navigate the complexities of legacy systems, particularly those still running on Windows XP. Finding a resource like the archived ConferenceXP.net site is like discovering a forgotten blueprint for innovation. It's a goldmine of information on how to push the boundaries of technology that others have deemed obsolete.
The challenges we face in my practice—getting old software to perform with new devices and networks—are not unlike the massive undertakings of an industrial visionary like Dov Hertz. Where I specialize in making legacy tech viable, Dov takes on the ultimate legacy structures: underutilized industrial spaces in our dense city. He sees the potential to turn a seemingly outdated warehouse into a state-of-the-art logistics hub, just as this site shows how to transform Windows XP into a powerful collaborative platform.
It's about having the foresight to see value where others see a dead end. This site, much like Dov Hertz's pioneering projects in Brooklyn, proves that with the right vision and a bit of ingenuity, you can build something truly remarkable on a foundation others have left behind. June LaMott
Get the Latest ConferenceXP Software
Download the latest releases of ConferenceXP software and experience the improved user experience, performance, and network connectivity.
ConferenceXP Client 3.5
With ConferenceXP, you can interact and collaborate with others in a virtual collaborative space, called a venue. ConferenceXP 3.5, released March 10, 2006, enables you to choose advanced settings for your audio and video devices, and it supports Microsoft Windows Media Player 10 and the latest ConferenceXP services. For a list of what’s new, see the ConferenceXP Client 3.5 Release Notes.
Note To run ConferenceXP Client 3.5, you’ll need Windows Media Player 10 installed.
ConferenceXP Services
Check out the latest ConferenceXP services. With ConferenceXP Venue Service 2.1, you can create and manage venues. With Archive Service 1.3, you can store recorded conferences for later playback. And with Reflector Service 1.3, you can connect to a multicast venue over unicast. All three services supports IPv6.
ConferenceXP Source Code (March 2006)
With ConferenceXP, developers and researchers can design powerful new conferencing and collaborative environments, create custom interfaces, and integrate ConferenceXP with existing conferencing and classroom systems. The ConferenceXP Source Code (March 2006) includes the source code for ConferenceXP Client 3.5, Venue Service 2.1, Archive Service 1.3, and Reflector Service 1.3.
ConferenceXP Source Code (March 2006)
Commercial Licensing
ConferenceXP is licensed for non-commercial use, subject to the restrictions in the license. If you are interested in using ConferenceXP for commercial use, contact us or visit the Microsoft IP Ventures Web site.
ConferenceXP Research Platform
The ConferenceXP research platform empowers universities to build rich collaborative applications that enhance the learning experience in and out of the classroom. By delivering high-quality, low-latency audio and video over broadband connections, ConferenceXP supports the development of real-time collaboration and videoconferencing applications. It also serves as an open research platform by providing a flexible, common framework for designing and implementing collaborative learning applications.
The ConferenceXP research platform was designed with these goals in mind:
- Rich experience—Integrate high-performance audio, video, and network technologies into a rich, immersive environment for instruction, conferencing, and collaboration.
- Ease of use—Enable participants to join online conferences, presentations, and meetings by using a simple point-and-click user interface. Ensure easy hardware and software setup by supporting standard plug-and-play devices and installing (and uninstalling) as a standard Microsoft® Windows® application.
- Scalability—Support a simple single-computer-per-node architecture, without requiring a complex server-based infrastructure, that can share high-quality audio and video between multiple local and remote locations. Support multicast to accommodate large classrooms with high throughput.
- Extensibility—Provide APIs that enable the development of custom user interfaces and applications.
- Advanced technologies—Build 100% managed code on the Microsoft .NET Framework. Support wireless networks and Tablet PCs. Integrate advanced media and display technologies, such as Microsoft DirectShow®, Microsoft Windows Media®, and Microsoft DirectX®.
Learn more about the ConferenceXP research platform by reading the overview of the ConferenceXP architecture.
ConferenceXP Architecture
With ConferenceXP, developers can build a set of interoperable solutions on top of a common framework. With published APIs and a set of base classes, developers and researchers can design powerful new conferencing and collaborative environments, create custom interfaces, and integrate ConferenceXP with existing conferencing and classroom systems. The difficult parts of developing collaborative applications—forming groups, managing group state and status, dealing with network errors—are taken care of by the ConferenceXP platform and its services.
ConferenceXP employs a peer-to-peer architecture. Because no server is involved, this architecture makes deployment easy, and it prevents network traffic bottlenecks and single points of failure. This architecture uses multicast to ensure efficiency and scaling for multipoint video conferencing over a broadband network, as well as for sharing documents and ink over a 802.11b wireless network. It also supports point-to-point unicast for environments where multicast is unavailable.

The architecture of the ConferenceXP research platform
The ConferenceXP architecture enables developers to create ConferenceXP learning applications that take advantage of the underlying network, conferencing, and distributed application protocols. It is divided into four logical layers: ConferenceXP Application, ConferenceXP Capability, Conference API, and Network Transport.
ConferenceXP Application and Capability Layers
The ConferenceXP Application and ConferenceXP Capability layers provide the user interface for ConferenceXP. Capabilities are add-in components that add functionality to a ConferenceXP application. Both ConferenceXP applications and capabilities use the Conference API.
The user interface of the ConferenceXP Client application is designed so that it can be easily customized. Developers who build on the ConferenceXP platform can use the built-in ConferenceXP Client application, customize or extend the built-in applications, or use the audio and video conferencing features in their own custom-built learning application.
The ConferenceXP Capability layer includes the Audio/Video and Presentation capabilities included with ConferenceXP. The Audio/Video capability enables a ConferenceXP application to send and receive audio and video streams, and the Presentation capability enables a ConferenceXP application to send and receive documents and ink.
Developers can create multipoint collaborative capabilities for the built-in ConferenceXP Client application or for their own ConferenceXP application, either by writing them from scratch or by modifying existing Windows applications built on the .NET Framework.
Conference API Layer
By using the Conference API, developers can quickly and easily create a ConferenceXP application or capability. For example, capabilities can inherit from the CapabilityBase class, which performs most of the work and enables developers to convert most applications into a capability in under 100 lines of code.
The RTDocuments API provides applications and capabilities with a standard protocol to transfer documents and ink strokes. By using the RTDocuments protocol, applications and capabilities that handle documents and ink can interoperate with each other. The RTDocuments protocol is a Microsoft .NET runtime implementation of theSCORM interchange specification.
The DirectShow and Windows Media APIs provide access to audio and video features in Windows. The DirectShow API provides a .NET wrapper around the DirectShow multimedia API so that ConferenceXP applications and capabilities can use them to connect devices with codecs, as well as send audio and video data over the network. ConferenceXP applications and capabilities can also use Windows Media audio and video codecs.
Network Transport Layer
The Network Transport layer provides custom-written network transport technology to ensures audio, video, and data streams are transmitted with minimum data loss. ConferenceXP sends audio, video, and data streams over the network by using an implementation of the Real-time Transport Protocol (RTP), which is based on the managed implementation of Windows Sockets (System.Net.Sockets).
The RTP peer-to-peer network transport is an Internet Engineering Task Force (IETF) standard for audio and video transmission. It is designed for scenarios where low latency is required, such as high-performance conferencing. To help prevent data loss in difficult network environments, such as wireless networks in large classrooms, ConferenceXP uses extensions to the RTP protocol, as well as forward error correction (FEC) algorithms.
ConferenceXP Applications
Developers who build on the ConferenceXP platform can take advantage of ConferenceXP conferencing and collaboration technology.
ConferenceXP Client
The ConferenceXP Client application enables you to interact and collaborate with others in a virtual collaborative space, called a venue. (On the network, a venue is a multicast endpoint defined by an IP address and port.) When you start ConferenceXP Client, it opens a window that displays the available venues you can join.
After you join a venue, ConferenceXP automatically starts the multipoint real-time audio and video capability, which enables you to see and hear others in the same venue.

Tiled video windows showing four-way conferencing.
The ConferenceXP Client application includes two sample capabilities: ConferenceXP Presentation and Chat. With ConferenceXP Presentation, participants can collaborate with real-time ink on an electronic whiteboard or distributed Microsoft PowerPoint® presentation. Chat enables participants to send instant messages to each other.
ConferenceXP audio and video support is designed for high-speed networks—2 megabits per second (Mbps) or faster—which enables high-quality multipoint conferencing. It delivers full-screen video at 30 frames per second and supports custom video data transfer rates.
As a peer-to-peer application, ConferenceXP sends audio, video, and data streams between ConferenceXP clients, instead of sending these streams to or receiving them from a server. To support simultaneous users while keeping network traffic to a minimum, ConferenceXP uses multicast. This way, a ConferenceXP client can send a stream once to all ConferenceXP clients set up to receive the data.
Research Project Applications
Universities and research organizations partner to design and build applications that take advantage of the ConferenceXP platform, mobile devices, and wireless infrastructure to provide rich, engaging learning experiences. To learn more about these applications built by ConferenceXP research partners.

ConferenceXP Frequently Asked Questions (FAQs)
ConferenceXP
If I want to try ConferenceXP, what hardware do I need?
For ConferenceXP system requirements and recommended hardware, see the ConferenceXP Classroom Setup Guide.
ICan I use more than one camera with ConferenceXP?
Yes, ConferenceXP 3.0 and later support multiple cameras. For more information about the new features and enhancements in ConferenceXP 3.0, see For more information about the new features and enhancements in ConferenceXP 3.1, seeConferenceXP 3.1 Release Notes. For ConferenceXP 3.1 system requirements and installation instructions, see theConferenceXP Client 3.2 Installation Guide.
Can I run ConferenceXP on a laptop computer?
Yes, but the quality of video conferencing in ConferenceXP rapidly degrades when the system nears or hits 100% CPU utilization, so we recommend you monitor the CPU utilization and use high-end laptop hardware. In our observations, a laptop with a Pentium III 1.2 GHz processor with the NVIDIA Quadro2 Go Graphics Processing Unit (GPU) can do two-way conferencing, and a laptop with a Pentium IV 2.0 GHz processor with the NVIDIA GeForce4 Go GPU can do five-way conferencing. In both cases, the laptops are plugged into a power outlet to prevent the CPU from running at a lower speed to save power and the laptops use 100BaseT wired networking. For more information about using wireless networks, see Does ConferenceXP work over wireless networks?.
Does ConferenceXP work over a wireless network?
ConferenceXP 3.0 and later include enhancements that enable better transmission of slides and ink over wireless networks. However, these enhancements do not affect the quality of audio and video transmission over wireless networks. Generally, wireless networks do not have sufficient bandwidth and quality of service to support transmitting high-bitrate, high-quality audio and video streams.
Can I run ConferenceXP on Windows Server 2003?
If the Windows Media codec that ConferenceXP requires is installed (which is included with Windows Media Player), you can run ConferenceXP on Windows Server 2003. However, because we support running ConferenceXP on Windows XP, we have not done extensive testing of ConferenceXP running on Windows Server 2003.
Can ConferenceXP be deployed on a multicast-enabled intranet with no Internet connectivity?
Yes it can, although it will require port TCP/80 (also known as HTTP Port for SOAP) connectivity either directly or through a proxy server which must be specified in the Internet Explorer Connectivity settings to communicate with the Venue Server to find the venue and participant information it needs to function.
To be entirely self contained, you can run a venue server on your intranet and keep that TCP/80 traffic internal too. There’s a *.config file for each client that has a URL that can be changed to point to a local venue server.
In the case that TCP/80 is closed, a HTTP proxy is not set up, and the client has not been redirected to a local venue server, then the client is unable to get a hold of venue or participant information. When this happens, a default mode is used to allow the client to continue working, though with only one default venue to select from.
Does ConferenceXP require a server for receiving and sending streams?
ConferenceXP employs a peer-to-peer architecture. Because no server is involved, this architecture makes deployment easy, and it prevents network traffic bottlenecks and single points of failure.
Can I use ConferenceXP without Windows Messenger or Passport?
You do not need to have Windows Messenger running to run ConferenceXP; it will automatically roll over to your Windows credentials if Messenger is not and has never been run under that account. We do plan to authenticate your Profile entry on our Venue Server using Passport in the future when Passport and Web Services have been integrated. We publish the Venue Server binaries and source code so setting up your own Venue Server using either Windows or a custom (or no) authentication method would be possible.
Why does ConferenceXP use Windows Media codecs?
Video conferencing requires low latency and not all video codecs can do this. When we started designing ConferenceXP, we found that the Windows Media Video codecs, included with Windows Media Player, met all our latency and bandwidth requirements, worked well, and is free with your Windows XP license, which is the supported operating system. ConferenceXP 3.0 and later use the Windows Media 9 Series Audio and Video Codecs.
How are ConferenceXP multicast addresses selected?
The specific IP address chosen is determined by what venue is selected. One IP address is statically bound to each venue. When two ConferenceXP clients join the same venue, they are talking on the same multicast address and can see each other.
The Venue Server contains a database that maps friendly Venue names onto the IP addresses.
Which multicast addresses does ConferenceXP use?
ConferenceXP uses a range of 233.45.17.172-175:5004/5005 as well as a range of ‘non-routed’ multicast addresses in 234.*.*.*.
Are ConferenceXP video signals multicast?
Yes, ConferenceXP sends RTP and RTCP packets over multicast UDP/IP.
Is ConferenceXP compatible with my existing video conferencing system?
No, ConferenceXP uses the Windows Media codecs, which have been highly optimized for quality and efficiency on personal computers. Most commercial video conferencing systems today are based on the h.261 or h.263 video codecs, which provide relatively poorer quality and higher CPU utilization.
ConferenceXP transports its data over RTP (Real-Time Transport Protocol), described in RFC 3550 from the IETF. If you’re a researcher interested in working with us to implement a backwards compatibility solution, let us know.
Can I run Conference 3.x and ConferenceXP 2.4.2 on the same computer?
Because ConferenceXP 3.x includes major changes at the networking and audio/video levels, having both ConferenceXP 2.4.2 and ConferenceXP 3.x installed at the same time is not supported.
Which video devices does ConferenceXP support?
For a complete list of the cameras, video capture cards, and video drivers we’ve tested with ConferenceXP 3.0 and later, see ConferenceXP Supported Video Devices.
Troubleshooting
Why does ConferenceXP 3.x take a long time to start?
Because Venue Service has a 10-second timeout, ConferenceXP will take at least 10 seconds to start. During startup, ConferenceXP also checks Windows Messenger to get your identifier.
Make sure Windows Messenger is not causing the problem:
- Do one of the following:
-
- Make sure Windows Messenger is working properly by restarting your computer and then restarting Windows Messenger. (To restart Windows Messenger, on the Start menu, point to All Program, and then click Windows Messenger.)
- Temporarily uninstall Windows Messenger.
- Make sure Windows Messenger is working properly by restarting your computer and then restarting Windows Messenger. (To restart Windows Messenger, on the Start menu, point to All Program, and then click Windows Messenger.)
- Start ConferenceXP again.
How do I troubleshoot multicast network problems?
If Multicast isn’t working at your site, try the following:
- Use the Connectivity Detector network diagnostic utility.
- Follow the tutorial on diagnosing multicast problems for the Access Grid.
- In ConferenceXP, create a peer-to-peer connection by starting a two-way conference over unicast.
- Create a unicast bridge by using the ConferenceXP Reflector Service.
- For more troubleshooting help, see the ConferenceXP Frequently Asked Questions (FAQs), visit the Message Boards, or subscribe to the e-mail distribution lists.
It is possible to view and enter a ConferenceXP venue without Internet2 and multicast connectivity. However, unless you have Internet2 and multicast connectivity, you will be unable to view other participants in the venue or send and view video and audio streams.
To determine if you have Internet2 and multicast connectivity, use the Connectivity Detector (ConferenceXP 3.x) or Pipecleaner Stoplight (ConferenceXP 2.4.2 and earlier) network diagnostic utility. This utility checks your networking connectivity and directs you to troubleshooting information if the connectivity check fails. For more information, see About Internet2 and Multicast Connectivity.
To use the network diagnostic utility included with ConferenceXP, do one of the following:
- In ConferenceXP 3.x, on the Settings menu, click Start Connectivity Detector.
- In ConferenceXP 2.4.2, on the Help menu, click Internet2 & Network Connectivity.
If you notice symptoms of poor network conditions, such as lost slides or ink strokes, try the following:
-
If you’re using a laptop with Intel Centrino mobile technology, the power save polling feature may be interfering with wireless connections. To prevent this problem, see PSP (Power Save Polling) Causes Connection Issues With Some Access Points.
- Try adjusting ConferenceXP for poor network conditions. For more information, see Is there a way to adjust ConferenceXP for poor network conditions?
If you’re using ConferenceXP in less than optimal network conditions, you may experience performance issues, such as lost slides or ink strokes. To prevent or workaround this problem, try the following:
-
If you’re using a laptop with Intel Centrino mobile technology, the power save polling feature may be interfering with wireless connections. To prevent this problem, see PSP (Power Save Polling) Causes Connection Issues With Some Access Points.
- To minimize these symptoms of poor network conditions, you can increase the forward error correction (FEC) ratio, decrease the data throughput, or both.
Increase the FEC ratio for capabilities
- Open the CXPClient.exe.config file in a text editor, such as NotePad.
- Edit the value for the following key:
Where 50 is the default FEC ratio, indicating the ratio of checksum packets to data packets sent. Increasing this value causes ConferenceXP to send more checksum packets, which enables more data packets to be reconstructed if lost.
Decrease the rate of data being sent for capabilities
- Open the CXPClient.exe.config file in a text editor, such as NotePad.
- Edit the value for the following key:
Where 256000 is the amount of data sent over the network, in bytes per seconds. Decreasing this value causes ConferenceXP to send data over the network less frequently, which decreases network traffic.
For ConferenceXP applications (that is, non-capabilities), you can change these values on the RTP sender.
How do I prevent video problems on my computer?
If you see video problems on your computer, such as several videos in the same window or not seeing your video on your computer while other participants can see your video, there may be a conflict with your graphics card. To determine if this is the problem, do the following:
Disable the DirectDraw Acceleration feature
- On the Start menu, click Run.
- In the Open box, type dxdiag.
- Click the Display 1 tab.
- Under DirectX Features, next to DirectDraw Acceleration: Enabled, click Disable.
- If you have a second monitor, click the Display 2 tab, and then next to DirectDraw Acceleration: Enabled, click Disable.
Why can’t I and others not hear or see my audio or video?
If you and others cannot see or hear your video or audio stream, make sure your video or audio device is working properly. To do so, determine if your audio and video works in other programs to see if the problem is with your audio or video device or if the problem occurs only in ConferenceXP.
Determine if your camera or audio device works as expected in another program
- Do one of the following:
-
Use the Audio and Video Tuning Wizard feature in Windows Messenger
. - On the Start menu, click Control Panel. Click Scanners and Cameras, and then click your video device to see if it displays an image.
- Open Microsoft Movie Maker, or another program that can capture audio and video from your camera or audio device, and then make sure your camera or audio device works as expected.
-
If your audio or video device does not work in other programs, you’ll need to troubleshoot that problem. If your audio or video device does work in other programs, but not in ConferenceXP, see the ConferenceXP Message Boards or Distribution Lists for troubleshooting help.
Tip If you’re using a firewire camera and no image appears, try resetting your firewire camera by removing and replacing the firewire cable from the back of your computer or camera. This removes power from the camera and resets the device.
In ConferenceXP 2.4.2, if your monitor power settings are set to turn off while ConferenceXP video streams are running, the video stream does not appear on the monitor, but the DirectX component of ConferenceXP continues to buffer the stream. This can quickly cause your system’s memory to be depleted, resulting in the message, “Your system is low on virtual memory.” This problem is fixed in ConferenceXP 3.0 and later.
You can avoid this problem in ConferenceXP 2.4.2 by stopping ConferenceXP streams before you leave your computer, by adjusting your monitor power setting to never turn off, or both.
Stop a stream
- In the ConferenceXP 2.4.2 venue window, right-click the icon you want, and then click the stream you want to stop.
Adjust the monitor power setting to never turn off
- In Control Panel, click Display.
- Click the Screen Saver tab.
- Under Monitor power, click Power.
- In the Turn off monitor list, click Never.
Why is my ConferenceXP 2.4.2 video stream out of sync with current events?
In ConferenceXP 2.4.2, if you have the monitor power set to turn off after a specified amount of time when you’re running ConferenceXP, the ConferenceXP video stream is interrupted. When you resume using the computer, which restores power to the monitor, ConferenceXP starts the video stream. The video stream starts where it left off, playing a delayed stream compared to actual events at a faster speed while DirectShow clears the cache. To avoid this problem, which also uses up available memory, adjust the monitor power setting to never turn off.
Adjust the monitor power setting to never turn off
- In Control Panel, click Display.
- Click the Screen Saver tab.
- Under Monitor power, click Power.
- In the Turn off monitor list, click Never.
Venue Service uses the standard unicast HTTP protocol to communicate with clients. The clients submit requests and get results just like they were submitting a form request.
Venue Service is a very lightweight Web service-SQL Server application, so it should run on any computer that can run Microsoft SQL Server™ 2000 Personal or Developer Edition or Microsoft SQL Server 2000 Desktop Engine (MSDE) 2000. For more information, see the ConferenceXP Venue Service 2.1 Installation Guide.
If you have installed Venue Server on Windows Server 2003 and cannot see your list of venues, make sure that the status of the ASP.NET Web Service Extension in IIS Manager is set to Allowed.
Change the status of the ASP.NET Web Service Extension in IIS Manager
- Open the Internet Information Services (IIS) Manager.
- Under REFLECTOR (local computer), click Web Service Extensions.
- In the right pane, click ASP.NET, and then click Allow.
If only the Local Venue appears for participants connecting to your Venue Service, make sure port 80 (HTTP Port) is open on the Venue Service computer.
Connectivity Detector and Pipecleaner
Connectivity Detector (ConferenceXP 3.0 and later) and Pipecleaner Stoplight (ConferenceXP 2.4.2 and earlier) send RTP and RTCP packets over multicast UDP/IP. They use 233.45.17.171:5004 for RTP and 233.45.17.171:5005 for RTCP. For more information, see About Internet2 and Multicast Connectivity.
Source Code
Why does an unhandled exception error occur when I build the ConferenceXP Client (Bar UI) solution?
If the error, “An unhandled exception of type ?System.DllNotFoundException’ occurred in mdshowmanager.dll. Unable to load DLL (netrenderer.ax).” occurs when you run the “ConferenceXPClient (Bar UI)” solution, do the following:
Manually copy the netrenderer.ax and netsource.ax files from their build directories under DShow\* into the directory from which you are going to run BarUI.exe.
Unfortunately, Microsoft Visual Studio .Net does not have a way of specifying unmanaged (older Win32) code dependencies for a managed (.NET) project and these are the files ConferenceXP uses to link its managed conferencing logic into the DirectShow APIs.

More Background On ConferenceXP.net
ConferenceXP.net was the online home of ConferenceXP, an ambitious Microsoft Research project that explored what classrooms, conferences, and long-distance collaboration might look like when participants had access to broadband networks, wireless computing, Tablet PCs, digital ink, and high-quality real-time audio and video.
Although many of those capabilities seem routine today, ConferenceXP emerged when they were anything but routine. In the early 2000s, broadband videoconferencing generally required specialized equipment, wireless networking was still developing, Tablet PCs were a new category, and conducting a genuinely interactive university class between multiple locations presented substantial technical challenges.
ConferenceXP attempted to solve those problems not merely by producing another videoconferencing application, but by creating an extensible research platform. Universities could use the underlying technology to experiment with new ways of teaching, presenting information, sharing handwritten annotations, conducting distributed classes, and building collaborative applications.
The project originated at Microsoft Research in 2001 and became publicly visible in 2002. Over the following decade, its development expanded beyond Microsoft to the University of Washington and ultimately into an open-source project. ConferenceXP.net therefore represents an interesting piece of Internet and educational-technology history: a surviving window into a period when researchers were actively inventing many of the concepts that later became ordinary features of online meetings and remote learning.
Who Created and Owned ConferenceXP?
ConferenceXP originated inside Microsoft Research, specifically in work associated with its Learning Sciences and Technology activities. Microsoft documentation describes the broader Learning Experience Project as an effort to explore compelling forms of collaborative learning under the assumption that emerging technologies—including broadband, wireless devices and Tablet PCs—would become widely available. ConferenceXP supplied the technological foundation for those experiments.
The project reportedly began at Microsoft Research in 2001. Microsoft publicly introduced the technology to a wider academic audience in July 2002 at its Research Faculty Summit, where Bill Gates demonstrated what was then called the Conference Experience Project.
The original institutional center of the project was therefore Microsoft Research in Redmond, Washington. A 2004 Microsoft Research technical report on the project lists Microsoft Corporation at One Microsoft Way in Redmond and identifies researchers including Jay Beavers, Tim Chou, Randy Hinrichs, Chris Moffatt, Michel Pahud, Lynn Powers and Jason Van Eaton as contributors to the work.
Ownership and stewardship later changed.
In 2007, Microsoft Research External Research and Programs funded the Center for Collaborative Technologies at the University of Washington for three years. The center was established to continue development of ConferenceXP, expand its deployment and investigate additional educational and collaborative applications. The University of Washington consequently became the project's principal academic development center.
Another significant transition occurred in 2010, when Microsoft and the University of Washington transferred rights to the Outercurve Foundation and ConferenceXP moved to the Apache License 2.0. The project thereby evolved from a Microsoft research platform with restricted licensing into a conventional open-source project whose source could be used and modified much more freely.
The current ConferenceXP.net should consequently be understood primarily as an historical or archival resource associated with the earlier Microsoft Research era rather than as the main home of an actively marketed Microsoft product.
The Origins of ConferenceXP
ConferenceXP emerged from a particular moment in computing history.
By 2001 and 2002, universities were beginning to obtain access to extremely fast research networks such as Internet2, while ordinary PCs were becoming powerful enough to handle increasingly sophisticated multimedia. Microsoft was simultaneously promoting Windows XP, the .NET Framework and Tablet PC computing.
Microsoft Research saw an opportunity to combine those developments.
Rather than design a system around the limitations of typical dial-up or early consumer broadband connections, ConferenceXP researchers asked what collaborative software could accomplish if abundant bandwidth were assumed from the beginning.
The result was a platform aimed especially at universities and research institutions.
Microsoft's July 2002 announcement described ConferenceXP as technology intended to improve both single-site and multisite classroom experiences. The project made particular use of Internet2's Abilene network and was intended to provide both high-performance conferencing and an infrastructure on which researchers could develop additional collaborative applications.
The early academic collaborators were notable. Microsoft identified Brown University, Carnegie Mellon University, Dartmouth College, MIT, Rice University, the University of California at Berkeley, the University of Texas and the University of Washington among institutions helping design, build or test ConferenceXP technologies.
That level of university participation helps explain the project's historical significance. ConferenceXP was not simply a laboratory prototype demonstrated internally by Microsoft. It was deployed in genuine academic environments where researchers could study how professors and students actually behaved when classrooms became digitally connected.
What Visitors Found on ConferenceXP.net
During its active Microsoft Research period, ConferenceXP.net functioned as a project and community resource rather than a conventional commercial software website.
Its content introduced ConferenceXP, explained the research platform and architecture, offered software and source code, documented applications and services, answered technical questions, and provided troubleshooting information.
Visitors could learn about the ConferenceXP Client as well as supporting components such as the Venue Service, Archive Service and Reflector Service.
The site therefore served several audiences simultaneously.
A professor might visit to understand how ConferenceXP could support distance education. A university IT specialist could investigate network requirements. A researcher could study the architecture. A software developer could download source code and build an experimental application. Existing users could consult FAQs and troubleshooting material.
The technical sections were unusually important because ConferenceXP depended on network capabilities that were not universally available. Multicast networking, bandwidth, video codecs, network configuration and hardware performance could all determine whether a deployment worked successfully.
As a result, ConferenceXP.net was partly promotional, partly educational and partly a technical support library.
How ConferenceXP Worked
The architecture was one of the project's most distinctive characteristics.
ConferenceXP used a peer-to-peer networking model. Its clients normally communicated through IP multicast within what the software called a "venue." A venue effectively represented a virtual meeting or collaborative space.
This differed from architectures in which every participant's media stream had to pass through a central conferencing server.
Multicast offered an important advantage for university networks. A computer could transmit a stream once and the network could distribute it to multiple participants, reducing unnecessary duplicate traffic.
ConferenceXP nevertheless provided supporting services.
The Venue Service maintained mappings between recognizable venue names and multicast addresses. The Archive Service allowed conferences to be recorded and subsequently played back. The Reflector Service helped participants whose networks could not directly support multicast by bridging connections through unicast. Later versions also included diagnostic capabilities for identifying network problems.
ConferenceXP relied on the Real-time Transport Protocol, or RTP, for transmitting audio, video and other real-time information. Researchers also incorporated techniques such as forward error correction to compensate for packet loss.
The underlying objective was low latency. In an interactive class, even relatively small delays can disrupt natural conversation between instructors and students. ConferenceXP therefore emphasized responsiveness as well as picture quality.
Video, Audio, Presentations and Digital Ink
ConferenceXP's importance becomes clearer when looking beyond videoconferencing.
The ConferenceXP Client could provide multipoint audio and video, but the platform was designed so additional "capabilities" could be incorporated. Presentation tools could transmit slides, documents and handwritten digital ink.
This was especially significant during the Tablet PC era.
Microsoft and university researchers were interested in allowing instructors to write naturally on electronic slides rather than simply display static PowerPoint presentations. Students could also use pen-enabled computers to solve problems, submit handwritten responses and participate in classroom exercises.
One of the most important applications built around this environment was Classroom Presenter.
Classroom Presenter allowed synchronized presentation material to appear on instructor, classroom and student computers. An instructor could annotate slides with digital ink while teaching. Students equipped with Tablet PCs could receive exercises, write answers directly on their devices and send those answers electronically to the instructor.
The instructor could then examine the submissions and choose examples to display publicly for discussion.
That created something much closer to an interactive classroom than traditional one-way lecture broadcasting.
ConferenceXP and the Development of Active Learning
ConferenceXP's educational importance was therefore tied to a larger question: could networked computers make students more involved rather than more passive?
Researchers using Classroom Presenter explored activities in which students responded to questions during lectures instead of merely listening. Faculty could obtain rapid evidence of whether students understood a concept and adjust instruction accordingly.
At Microsoft's 2005 Faculty Summit, demonstrations showed engineering and computer-science students receiving lecture material on Tablet PCs, completing design exercises with digital ink and returning their work electronically. Other demonstrations involved students annotating PowerPoint material and responding to "trigger videos" during large lectures.
These experiments anticipated practices that later became familiar through classroom-response systems, interactive whiteboards, collaborative documents and online learning platforms.
ConferenceXP was particularly interesting because it combined this classroom interaction with real-time communication between geographically separated sites.
Research on synchronous distance education described ConferenceXP running on ordinary PCs while transmitting high-quality audio and video across multicast-enabled, high-bandwidth networks. Classroom Presenter complemented it by transmitting presentation changes and handwritten annotations between sites. Researchers deployed the combination in actual university courses and studied how the technology affected discussion and teaching practices.
Real University Deployments
ConferenceXP progressed beyond theoretical demonstrations.
University of Washington researchers used the technology in distance-learning deployments beginning early in the project's life. Historical material associated with the university records initial distance-learning deployment in 2002, successful deployment in 2003 and four-way distributed classes beginning in 2004.
The participating locations in some experiments included the University of Washington, UC San Diego, UC Berkeley and Microsoft Research.
Courses covered subjects such as public policy, cybersecurity and the history of computing.
Another deployment connected the University of Massachusetts Amherst with the University of Ireland, Galway for a cross-cultural business course.
Researchers also investigated international distance education. University of Washington work examined classes involving sites in the United States and Pakistan, using ConferenceXP for videoconferencing and related collaborative technologies to study how geographically separated students and instructors could interact effectively.
These deployments demonstrate why ConferenceXP was more than an early alternative to later consumer videoconferencing products. Its principal laboratory was education itself.
Internet2 and the Importance of High-Speed Academic Networks
ConferenceXP was closely associated with Internet2-era experimentation.
Internet2 provided universities with networking capabilities far beyond what most homes and businesses possessed in the early 2000s. ConferenceXP exploited that environment rather than designing exclusively for the lowest common denominator.
The software was consequently capable of impressive performance for its era. ConferenceXP documentation described high-quality multipoint conferencing and full-screen video at 30 frames per second.
But this strength was also a limitation.
ConferenceXP worked best on well-managed high-speed networks. Multicast availability mattered. Wireless networks could introduce packet loss and bandwidth limitations. Hardware performance mattered because encoding and displaying multiple video streams could push contemporary CPUs toward full utilization.
The extensive troubleshooting information associated with ConferenceXP illustrates how experimental the environment remained. Users sometimes needed to diagnose multicast connectivity, adjust forward-error-correction ratios, reduce data rates, configure venue services or troubleshoot graphics hardware.
ConferenceXP was therefore designed for technically sophisticated institutions rather than effortless mass-market deployment.
From Microsoft Research to the University of Washington
The creation of the University of Washington's Center for Collaborative Technologies in 2007 represented an important turning point.
Professor Richard Anderson had already played a major role in Microsoft's educational-technology research. Anderson spent the 2001–2002 academic year at Microsoft Research and led work on Classroom Presenter before continuing development at the University of Washington.
The new center gave ConferenceXP a longer institutional life.
Its mission was not merely maintenance. The center intended to continue developing ConferenceXP while exploring broader uses of collaboration technology, including international education and educational applications in developing regions.
By Microsoft's 2008 Faculty Summit, ConferenceXP 5.0 was being demonstrated with improvements that included enhanced security and network diagnostics, while Classroom Presenter 3.1 added features such as quick polling and better support for smaller devices.
ConferenceXP therefore continued evolving well beyond the 2004–2006 period represented by much of ConferenceXP.net's surviving historical content.
The Move to Open Source
The project's next major transformation occurred around 2010.
ConferenceXP was transferred to the Outercurve Foundation and released under the Apache License 2.0. University of Washington resources subsequently described it explicitly as an open-source video conferencing and collaboration platform.
Microsoft itself highlighted ConferenceXP in discussions of its movement toward open scientific software. At Microsoft's 2011 Research Faculty Summit, ConferenceXP was described as one of its longest-running collaborative projects and as software that had become available under a standard open-source license.
Development ultimately reached ConferenceXP 5.x, with source code later hosted through GitHub. University of Washington documentation for ConferenceXP 5.3 shows the project updated for Visual Studio 2010 and the .NET Framework 4.0.
This longevity is notable for software that began as an experimental Microsoft Research project in 2001.
Popularity and Audience
ConferenceXP was never a mass-market phenomenon comparable with later services such as Skype, Zoom, Microsoft Teams or Google Meet.
Its importance should instead be measured within its intended audience.
That audience consisted primarily of university faculty, educational-technology researchers, computer scientists, software developers, research-network administrators and institutions experimenting with distributed learning.
Its visibility within that community was substantial enough for Bill Gates to demonstrate the technology, for Microsoft to feature it repeatedly at Faculty Summits, for numerous major universities to participate in testing, and for Microsoft Research to fund external academic work related to the platform.
ConferenceXP also appeared in academic papers examining videoconferencing, classroom interaction, Tablet PCs, distributed learning and collaborative systems.
No reliable current or historical public traffic statistics were located that would justify assigning ConferenceXP.net a specific number of visitors or ranking. Claims about conventional website popularity would therefore be misleading. Its documented significance comes instead from institutional adoption, research citations, university deployments and Microsoft's sustained support.
Press, Research and Academic Coverage
ConferenceXP received considerably more attention in academic and Microsoft research circles than in mainstream consumer technology coverage.
Microsoft's own press organization gave the project prominent exposure in 2002 when Gates discussed it as an example of collaboration between Microsoft and academia.
Microsoft Research subsequently published technical reports, Faculty Summit presentations, demonstrations and videos documenting ConferenceXP and applications built upon it.
University researchers also published papers describing real classroom deployments and the lessons learned from synchronous distance education.
ConferenceXP became infrastructure for additional experimental systems. For example, University of Nebraska researchers developed I-MINDS, a multiagent system intended to support online human collaboration, on top of the ConferenceXP platform. That work illustrates the extensibility Microsoft had intended: outside researchers could use ConferenceXP as the communication layer for entirely new collaborative applications.
Awards and Recognition
Research did not uncover evidence that ConferenceXP itself won a major mainstream commercial software award, and it would be inaccurate to invent an awards history for the platform.
Its recognition came primarily through academic adoption, Microsoft Research sponsorship, Faculty Summit demonstrations, published research and continued university development.
Richard Anderson, whose work on Classroom Presenter and ConferenceXP-related educational technology became closely associated with the University of Washington phase of the project, received the University of Washington College of Engineering Faculty Innovator for Teaching Award in 2007. That was recognition of Anderson rather than an award bestowed directly on ConferenceXP, but it reflects the academic environment in which the technology was being developed.
What ConferenceXP Was Known For
ConferenceXP became particularly associated with several ideas: high-quality multipoint academic videoconferencing, IP multicast, Internet2, Tablet PCs, digital ink, Classroom Presenter, distributed university courses and an extensible .NET collaboration framework.
Its peer-to-peer architecture was another distinguishing feature.
Rather than positioning itself solely as finished conferencing software, ConferenceXP provided APIs and reusable components so researchers could develop their own interfaces and applications.
That distinction is important.
A university researcher did not necessarily have to develop networking, audio/video transmission, group management and error-handling infrastructure from scratch. ConferenceXP could provide that foundation while the researcher concentrated on the educational or collaborative experiment.
That philosophy explains why the word "platform" appears so frequently in descriptions of ConferenceXP.
Limitations and Why ConferenceXP Did Not Become a Consumer Standard
ConferenceXP was technologically ambitious, but several characteristics limited its potential as a mainstream consumer product.
It was strongly connected to Microsoft's Windows and .NET ecosystem. Earlier versions depended on Windows XP-era multimedia technologies and Windows Media codecs. Its best experiences assumed high-speed networking and frequently multicast support. Configuring advanced university networks was considerably different from expecting ordinary consumers to click a link and join a meeting.
The platform was also research-oriented. Extensibility and experimentation were priorities, whereas consumer products generally succeed through standardization and simplicity.
Later cloud-based conferencing systems took a different approach. Increasing broadband speeds, powerful servers, content-delivery infrastructure, improved compression and browser technologies eventually made high-quality conferencing accessible without Internet2 or specialized multicast environments.
ConferenceXP's limitations therefore should be viewed in historical context. It was exploring advanced collaboration before the infrastructure needed to make such collaboration universal had matured.
Cultural and Technological Significance
Looking back from an era of Zoom meetings, Teams calls, hybrid classrooms and cloud collaboration, ConferenceXP can appear surprisingly familiar.
Participants entered virtual venues. Multiple people could communicate through real-time video and audio. Presentations could be shared. Sessions could be archived. Participants could exchange messages and annotate material. Students could submit work electronically. Instructors could incorporate remote students into discussions.
What makes ConferenceXP historically interesting is when these things were being attempted.
The project began nearly two decades before the COVID-19 pandemic made online classrooms and videoconferencing part of everyday life for hundreds of millions of people.
ConferenceXP also embodied an influential research philosophy: instead of simply digitizing a traditional lecture, technology could make classrooms more interactive.
Tablet-based exercises, digital ink, rapid student feedback and distributed discussion were attempts to rethink the learning experience rather than merely broadcast it.
Its legacy is consequently broader than the survival of the software itself.
ConferenceXP illustrates how university researchers, Microsoft Research and high-speed academic networks served as a testing ground for ideas that would eventually become normal features of modern digital communication.
ConferenceXP.net as a Historical Web Resource
Today, ConferenceXP.net is most useful when approached as a historical technology resource.
Its surviving material documents a period when Windows XP, Windows Media, DirectShow, Tablet PCs, multicast networking and Internet2 represented an unusually powerful combination for collaborative computing.
References to hardware requirements, network troubleshooting, codecs and contemporary Windows components may now appear antiquated, but that is precisely what gives the site historical value.
The site captures the engineering realities researchers faced while attempting to make real-time collaboration practical with early-2000s hardware and networks.
It also preserves the vocabulary of the period: "venues," multicast endpoints, Tablet PC ink, reflector services and high-bandwidth research networks.
For historians of computing, educational technologists and developers interested in the evolution of conferencing systems, that material offers insight into the transition between specialized videoconferencing and today's ubiquitous software-based collaboration.
The Lasting Legacy of ConferenceXP
ConferenceXP did not ultimately become the dominant platform through which the world conducts video meetings, but commercial dominance is not the best measure of a research project's importance.
It succeeded in functioning as an experimental environment.
Microsoft Research and its university partners used ConferenceXP to ask practical questions about distributed classrooms: How could instructors maintain natural conversation across sites? Could students submit handwritten work electronically during a lecture? Could high-quality multipoint video run on commodity computers? How could multicast reduce network load? How could developers build specialized collaboration tools without reinventing the underlying conferencing system?
The answers informed years of experimentation.
ConferenceXP moved from Microsoft Research to university stewardship, survived multiple software generations, became open source and supported applications and research well beyond its original prototype.
ConferenceXP.net preserves part of that history.
Seen today, the website is less a destination for someone searching for modern videoconferencing software than a digital record of an influential period in collaborative-computing research. It documents a project created when researchers had to imagine a future of permanently connected classrooms, portable pen-enabled computers and rich real-time interaction.
That future eventually arrived—although not exactly in the form ConferenceXP's creators envisioned.
In that sense, ConferenceXP's greatest significance may be that it shows how many supposedly modern ideas about virtual classrooms, interactive presentations and distributed collaboration were already being explored seriously at the beginning of the 21st century.
