The Answer Bank - The Answer Bank is the UK’s leading question-and-answer site.
Documize - Enterprise-grade wiki and knowledge management platform
Blurtit - Blurtit is a Q&A website. You can ask a question or answer on any question.
Boardist - Personal workspace for all the data
AllAnswered - Your Team's Collective Brain All-In-One Knowledge Management System Wiki + Q&A + Workflow + AI
ReadTheDocs - Spend your time on writing high quality documentation, not on the tools to make your documentation work.