ManualsLib - Just enter the keywords in the search field and find what you are looking for!
FaqFox - Find the questions your target audience is talking about
Dozuki - Dozuki is a web-based tool for creating and distributing step-by-step documentation.
HelpDocs - Educate your users with a super simple knowledge base that’s built for teams just like yours.
Manuzoid - Repository that includes user manuals for various products
Dr.Explain - Dr.Explain software is a help file authoring tool.