extremely easy to manage tool to create knowledge base or wikis, in one word, simplicity at its best. You can create nested page in a tipical wiki style that you can share with one or more clients or coworkers. The edit tool also work kinda flawlessly.

Easy to get started, lots of samples and walkthroughs available

I love being able to organize all my projects and workspaces with sub-folders. Each document has robust features to pull in different types of content types. You can easily create new documents, collaborate on those docs with team members. You can share a space either publicly or privately. This can be used as a way to collaborate with clients and team members as well as create a public facing knowledge base.