ManualsLib - Just enter the keywords in the search field and find what you are looking for!
Dozuki - Dozuki is a web-based tool for creating and distributing step-by-step documentation.
Internet Archive Manual Library - Internet Archive Manual Library is your go-to source for viewing the big collection of datasheets, instructions, and guides written for a wide range of products.
DocGen - Static website generator
Manuzoid - Repository that includes user manuals for various products
openSourceCM - Web-based legal document processing and contract management