Laserfiche - Laserfiche offers powerful document management software solutions that are easy to implement and easy to use.
HelpNDoc - What is HelpNDoc ? Easy to use yet powerful help authoring environment which can generate various documentation formats from a single source.
DocuWare - DocuWare is a next-gen document management system that is specially designed for transferring paper-based and digital assets into collective resources.
ManualsLib - Just enter the keywords in the search field and find what you are looking for!
IBM FileNet - Enterprise Content Management platform for large businesses
Manuzoid - Repository that includes user manuals for various products