Drupal is a modular content management system, forum, blogging and community engine. It is database driven and can be used with MySQL, MariaDB, PostgreSQL, and SQLite. Its features include (but are not limited to) discussion forums, Web-based administration, theme support, a submission queue, content rating, content versioning, taxonomy support, user management with a fine-grained permission system based on user roles (groups), error logging, support for content syndication, locale support, and much more. It is considered to be an excellent platform for developers due to its clean code and extensibility, and it can also be used as a Web application framework.
The GNU Gatekeeper is a free H.323 gatekeeper based on the OpenH323 project. You can use it to manage a Voice-over-IP network and let endpoints (e.g., Netmeeting) communicate through symbolic names. It also has an external interface for billing and other applications. It runs on a number of Unix versions (including Linux and Solaris) and Windows.
dyn-host-filter is a stand-alone application used to restrict the access to qmail based on the client's hostname/IP. Each incoming entry is compared to a user-defined list of regular expressions. dyn-host-filter may reject a matching entry by modifying the RBLSMTPD env. variable used by tcpserver.
PMS/PyPubSub (short for Python Message Service / Python based Publish Subscribe) is a framework for implementing a publish subscribe mechanism into a Python application. A python process somewhere in the network publishes one or more topics which consist of Python objects. Multiple processes in the network can subscribe to fresh updates of the published topics. A publisher and its subsribers are fully decoupled. The datatype of a topic can be freely defined and changed at runtime. New publishers and subscribers can easily be added at runtime.
Pymailheaders is a small GTK+ program which displays mail headers in your mail box. It is an innovation of xmailheaders, with a few more handy features like new mail highlighting, multi-language support, lauching regardless of network connection status, and auto-reconnecting. IMAP4 and POP3 protocols and XML feeds (including Gmail) are supported.