Enigmail is an extension for the mail client of Mozilla, Netscape 7.x, and Mozilla Thunderbird that allows users to access the authentication and encryption features provided by the popular GnuPG software. It can encrypt/sign mail when sending, decrypt/authenticate received mail, and import/export public keys. It supports both the inline PGP format and the PGP/MIME format, which can be used to encrypt attachments, and is cross-platform, although binaries are supplied only for a limited number of platforms. Enigmail uses inter-process communication to execute GPG to carry out encryption/authentication.
The Fedora software is based on an architecture known as FEDORA (Flexible Extensible Digital Object and Repository Architecture). The software takes advantage of distributed (or local) Web services, and makes representations of objects (called disseminations) available via HTTP. It is particularly good at handling complex digital objects where source datastreams and behaviors are distributed. There are two binary distributions (server and client), and a source distribution (including all libraries and source code needed to build any distribution).
Pike is an interpreted, object-oriented, dynamic programming language with a syntax similar to C. It includes a powerful modules system that, for instance, has image manipulation, database connectivity and advanced cryptography. It is simple to learn, does not require long compilation passes and has powerful built-in data types allowing simple and fast data manipulation.
SiteFusion allows object-oriented PHP applications to operate as OS-native applications through a XULRunner-based thin client. The client connects to the SiteFusion daemon through an ordinary Web server, and applications run in separate continuous processes. Two-way communication is enabled, without the need for additional Web server configurations. The implementation of the XUL framework in a PHP class structure includes an implementation of the Mozilla tree view optimized for very large trees, supporting drag-and-drop, editable cells, and sorting.
ff3sudoku is an add-on that features an engine for playing Sudoku puzzles. It can generate random puzzles, but it also detects and imports Sudokus from several Web sites, including websudoku.com, sudokupuzz.com, sudoku.com.au, and others. There is also a stand-alone version working in Firefox 3+ and GoogleChrome.
The par utility creates and manipulates PalmOS database (.pdb) and resource (.prc) files. Par is designed to be a Swiss army knife for managing these files. It's a command line tool, and not for the faint of heart, but it's very handy and replaces a bunch of little utilities that you might otherwise use.