Here are the most recent articles and resources I've found in my del.icio.us favorites list that include the tags "Collaboration" and "Tool." I include an earlier post of mine on the same topic which provides more links:
Williams Instructional Design "Collaboration Tool" post from 2008
From their website -
The Software: Chamilo is a new project that opts for open source in a radical way. It aims at bringing you the best e-learning and collaboration platform in the open source world. At its start it will come in two flavours: Chamilo 22.214.171.124, the direct successor of Dokeos 126.96.36.199, and Chamilo 2.0, that has reached the final stages of development, a new taste of e-learning and much more, that will definitely bring fresh and creative tools to you.
The Association: Chamilo is also a brand owned by everybody who is part of the association Chamilo.org. The trademark is not and will never be owned by a single trademark holder.
Aiming to protect the software and to keep it free and open, an association has been created to watch over the future of Chamilo software.
* Easy creation of educational content
* Easy installation on web hosting solutions
* Tracking of users results, allowing for methodology improvements
* Clean interface, letting user focus on learning
* Synchronous and asynchronous communication channels
* Many tools allowing for all learning types (visual, auditive, practical, serious games)
* Extensive documents management
Learning Tools Compendium of Collaboration Tools: From the Centre for Learning & Performance Technologies, a learning tools directory of stand-alone tools suitable for individuals to work and learn more effectively with others - as well as on their own.
Learning Tools Compendium of Social Networking & Collaboration Spaces: From the Centre for Learning & Performance Technologies, a directory of social media platforms that include public social networks as well as tools to create private collaborative, social spaces for groups or communities, as well as enterprise collaboration systems (with multiple groupsites).
Scribblar.com: A free, online tool that provides multi-user whiteboard, live audio, image collaboration, text-chat and more.
Wiggio: From their website... "Wiggio is an online toolkit that makes it easy to work in groups. You can basically make a Wiggio group for any type of group you're in (a team, organization, business, project, social group, etc.) and Wiggio provides you with everything you need to simply communicate and collaborate within the group." The tools include mass messaging (emails, text messages, voicemails), scheduling, file sharing and editing, polling, conference calling, video conferencing, and project management.
Social Media and Learning - Part 3: Collaborative Working & Learning: From the Centre for Learning & Performance Technologies, the third of a three part article that looks at how key social media tools can be used for learning, development and performance support. Social media tools, support social interactions and connections with people, collaboration and sharing and the creation of user-generated content, and are helping to build a new phase of (e-)learning – often referred to as E-Learning 2.0 or Social Learning.
LucidChart: A free, flowchart/org chart collaboration tool.
Etherpad: A web-based word processor that allows people to work together in real-time.
Dabbleboard: A free online whiteboard collaboration application.
15 free tools for web based collaboration: From the Six Revisions blog, a review of 15 online tools.