Seahorse is a GNOME application for managing encryption keys. It also integrates with nautilus, gedit and other places for encryption operations.

Cecil is a library written by Jb Evain (http://evain.net/blog/) to generate and inspect programs and libraries in the ECMA CIL format.

In simple English, with Cecil, you can load existing managed assemblies, browse all the contained types, modify them on the fly and save back to the disk the modified assembly....

The Cyrus IMAP server differs from other IMAP server implementations in that it is generally intended to be run on sealed servers, where normal users are not permitted to log in. The mailbox database is stored in parts of the filesystem that are private to the Cyrus IMAP system. All user access to mail is through the IMAP, POP3, or KPOP protocols....

An O/R Mapper for Ruby based on the DataMapper pattern.,

LAMP port to 770 to allow developers to test and debug code in free small time.

mpg123 is a real time MPEG 1.0/2.0/2.5 audio player for layers 1,2 and 3 (MPEG 1.0 layer 3 aka MP3 most commonly tested). Among others working with Linux, MacOSX, FreeBSD, SunOS4.1.3, Solaris 2.5, HPUX 9.x, SGI Irix and Cygwin.

gv allows to view and navigate through PostScript and PDF documents on an X display by providing a user interface for the ghostscript interpreter.

Blueprint is a CSS framework, which aims to cut down on your development time. It gives you a solid foundation to build your project on top of, with an easy-to-use grid, sensible typography, useful plugins, and even a stylesheet for printing.

EclEmma is a Java code coverage tool for Eclipse. It launches from within the workbench like JUnit test. Runs can directly be analyzed for code coverage.
Coverage results are immediately summarized and highlighted in the Java source code editors. EclEmma does not require modifying your projects or performing any other setup....

Smultron is a free text editor for Mac OS X, which is both easy to use and powerful. It is designed to not confuse newcomers nor disappoint advanced users. It has all the advantages of an Cocoa application and some of its features are tabs, line numbers, support for syntax colouring for many different languages, functions list, support for text encodings, snippets, a toolbar, a status bar, preview, split window, multi-document find and replace with regular expressions, possibility to show invisible characters, authenticated open and saves, command-line utility, full screen editing and running commands and scripts from within the application....