The 64 Studio Platform Development Kit (PDK) is a version control system for GNU/Linux distributions, allowing the creation and management of many different projects, based on Debian and Ubuntu sources. PDK is written in Python, and the source code is well commented and contains documented examples.
6jack is a framework for testing, analyzing, and fuzzing network applications. 6jack runs a command, intercepts calls to common network-related system calls, and passes them through an external filter. A filter can be written in any language supporting the MessagePack serialization library. 6jack is especially useful for writing tests for clients and servers, debugging and reverse engineering protocols, sketching filtering proxies, and fuzzing.
::mound:: is a software development management platform. ::mound:: provides simple project management with lots of power, but stays out of the way. ::mound:: is methodology independent and is designed for agile software development. It allows for tracking of bugs, tasks, and projects.
@ (monkey-tail) is a simple collection of simple commands. Built-in commands include listing of memory usage and open files for a process (by name or PID), running processes detached from a terminal, and running a program only once. @ can merge external pieces of code into itself to provide extra commands. Additionally, these "externals" can then be updated from their source. Currently there are externals available for extracting archive files (including nested archives), setting the GNOME desktop wallpaper image, and for replicating @ to another host via SSH. Externals can easily be written, as they are simply collections of Bash functions. It is completely self contained and self modifying, and is implemented in a single file.
@-Tension CMS is a content management system which features XHTML strict compliance, a WYSIWYG HTML editor, complete accessibility (WAI compliance), flexible user and rights management, in-place authoring/administration via a Web browser, comprehensive built-in access statistics, and human-readable URLs.