Documize - Enterprise-grade wiki and knowledge management platform
The Answer Bank - The Answer Bank is the UK’s leading question-and-answer site.
Boardist - Personal workspace for all the data
Ask Me Help Desk - Ask Me Help Desk is a question-and-answer site.
ReadTheDocs - Spend your time on writing high quality documentation, not on the tools to make your documentation work.
Blurtit - Blurtit is a Q&A website. You can ask a question or answer on any question.