Alfresco
- A cross-platform Enterprise Content Management (ECM) including Document Management, Collaboration, Records Management, Knowledge Management, Web Content Management and Imaging. Provides multilingual support.
AurigaDoc
- A Java-XML-XSL-based documentation tool for writing XML documents and converting them to other open formats such as HTML.
Cxref
- A C cross-referencing and documentation tool.
DOC++'s Home Page
- A documentation system for C, C++, IDL and Java; generates both TeX output for hard-copies and HTML output for online browsing of documentation.
Doxygen
- A documentation system for C++, C, Java, Objective-C, Python, IDL (Corba and Microsoft flavours) and also PHP, C#, and D. Translated into 30+ languages. Latest release is 1.7.2, 2010-10-09.
KnowledgeTree - Document Management System
- An open source document management system. Commercial editions (with full technical support) are available as well as the free open source edition. N.B. Users are required to fill out a form to obtain the open source edition.
Owl Intranet Engine
- A multi-user document repository (knowledge base) document manager and/or document management system (DMS) for a corporations, small business, groups of people, or individuals.
ROBODoc - Automating Software Documentation
- Automated software documentation that syncs up source code and documentation in a single file. Latest release is 4.99.34, 2007-06-23.
The phpDocumentor Homepage -- PHP Auto Documentor
- The current standard auto-documentation tool for the PHP language. It can be used from the command line or a web interface to create professional documentation from PHP source code. Latest stable release is 1.4.2, 2008-03-31.