Subversion is a version control system. Originally designed to be a compelling replacement for CVS in the open source community, it has far exceeded that goal and seen widespread adoption in both open source and corporate environments. The Subversion project produces Subversion's core libraries (written in C), a fully functional command line client (svn), repository administration programs, API bindings for various languages (Perl, Python, Java, Ruby, etc.), and various additional tools and scripts.
Apache SpamAssassin is an extensible email filter that is used to identify spam. Once identified, the mail can then be optionally tagged as spam for later filtering. It provides a command line tool to perform filtering, a client-server system to filter large volumes of mail, and Mail::SpamAssassin, a set of Perl modules allowing Apache SpamAssassin to be used in a wide variety of email systems.
Piggydb is a flexible and scalable knowledge building platform that supports a heuristic or bottom-up approach to discover new concepts or ideas based on your input. You can begin with using it as a flexible outliner, diary or notebook, and as your database grows, Piggydb helps you to shape or elaborate your own knowledge. Piggydb is a Web application provided as a self-contained package that contains a Web server and database engine.
Apache OpenMeetings is a multi-language customizable video-conferencing and collaboration system. It supports audio/video and allows you to see the desktop of any participant. It includes a whiteboard, the ability to import a variety of image formats, invitations, a moderation system, backup and language modules, private and public conference rooms, and the ability to record meetings. The project also provides integrations for Asterisk, Jira, Confluence, Moodle, Sakai, and SugarCRM, and connectors for LDAP and ADS.