The beauty of open source technology - (technology that is free, and created by hundreds if not thousands of programmers from across the globe) - is that it can serve as the basis of many awesome things :) MindTouch is a company that has done just that. Their technology is based on MediaWiki, the technology behind Wikipedia.
Essentially, the company has created a tool that takes your organization's most important, strategic content and organizes it in a way that makes sense. This translates to better internal communication, more customers, and a decrease in costs. Additionally, the software can also be used for collaboration purposes.
MindTouch has many well-known clients, but the seal approval comes from Mozilla. The Mozilla Development Community wiki – where developers volunteer their time to create Firefox – is powered by MindTouch.
For most organization, however, finding the right technology is only half the problem. The other half is helping your organization cultivate a culture or collaboration. It is important to provide your employees with the understanding of WHY collaboration matters, HOW it will improve their lives, and best practices. (As well as training them on the new technology). In other words, you need to convert your employees to collaboration lovers in order for the collaborative technology, such as this one, to make a difference.
Keep in mind - at the end of the day, the technology is not what matters; it’s bringing together the collective brainpower of your employees that does. In my experience, this is not easy step, but a vital step to stay competitive in today's market.
I just stumbled upon an interactive list of cool collaborative tools, organized by category. Very cool and obviously a lot of research has gone into it. I encourage you to check it out: 
