The Evidence Hub: The Evidence Hub is a new kind of collaborative knowledge building tool which put ‘evidence’ gathering and sharing at the at the core of the knowledge building process.
Through the Evidence Hub, as members of a community, people are called to contribute and debate on what is the evidence-based practice and research that can move the community forward. To do so users can:

• Map the social ecosystem— add People, Projects and Organizations and monitor their networks
• Map the discourse ecosystem — add Issues, Solutions, Claims, Evidence and Resources to the debate

These are the core building blocks for the community generated evidence-based knowledge; and the Evidence Hub is the place where this knowledge can be explored, searched and visualized in many interesting ways. We have built so far several Evidence Hub for differnt Communities of Practices such as:
The OER Evidence Hub: for Open Educational Movement
The Ed-Futures Evidence Hub: For local Teachers and Educational Futures researchers
The Research By Children and Young People Evidence Hub
The Health Visitors Community of Practice Evidence Hub (Private Website)

Cohere: Viewed through the lens of contemporary web tools, Cohere sits at the intersection of web annotation (e.g. Diigo; Sidewiki), social bookmarking (e.g. Delicious), and mindmapping (e.g. MindMeister; Bubbl), using data feeds and an API to expose content to other services.
Cohere combines collaborative web annotation of Web Pages to knowldge mapping. Users can annotate Webpages with their ideas, issues, arguemnts and then structure those in forms of knowldge /arguments maps that can be visualized as network of annotations. Cohere also offers several social features such as voting on ideas/connections and a social network visualization built from the anlaysis of the number and type of connected ideas between users. To know more about cohere check the following publications[1,2]

Compendium: The action research platform around which the "Compendium team" is developing the Hypermedia Discourse approach is Compendium. This supports real time knowledge construction in meetings, or can be used for personal information management and reflection. This is a robust hypermedia mapping tool that is freely available with a growing community of practice, and developer community. Now integrated with the Moodle virtual learning environment as part of the LabSpace.
Compendium is also finding application in the arenas of e-Democracy (Napier Univ. UK), and e-Participation in policy formulation (Griffith Univ., AU). Simon Buckingham Shum also coordinates the GlobalArgument.net experiments mapping contemporary policy debates, such as the Iraq invasion.
Screencasts: Knowledge Mapping Open Educational Resources

CoPe_it! is a Web-based system that attempts to assist and augment collaboration among members of Communities of Practice by facilitating the creation, leveraging and utilization of the relevant knowledge.(Responsible: Manolis Tzagarakis (tzagara@cti.gr) - Nikos Karacapilidis (karacap@cti.gr))
It has been developed within the PALETTE Project (Pedagogically sustained Adaptive Learning through the Exploitation of Tacit and Explicit Knowledge)

FM (the Flash-Meeting project)
FM is an academic research project developed in KMI (Open University, MK) ,that allows a dispersed group of people to meet from anywhere in the world in a “virtual meeting room” in which they can see and talk to each other. The only equipment FM request is web-cam and Internet connection...the rest is all fun!