GTK, which stands for the Gimp ToolKit, is a library for creating graphical user interfaces. It is designed to be small and efficient, but still flexible enough to allow the programmer freedom in the interfaces created. GTK provides some unique features over standard widget libraries.
The Lightweight Java Game Library is a native binding for OpenGL and OpenAL written with game developers in mind. It allows the full OpenGL and OpenAL APIs to be exposed without the penalties associated with competing methods, nor the limitations of APIs such as Java3D. Tutorials and demos are available, and Windows, Linux, and Mac OS X are supported.
NSFileHandleExt is an Objective-C extension (Cocoa/GNUstep) for the NSFileHandle class (which handles files/sockets). This extension provides support for much easier network programming for protocols like HTTP, IRC, telnet, etc. (everything that sends messages in lines suffixed by \n).
QDS is a library for Qt developers which provides cross-platform access to additional features of the various desktop APIs. The main goal is to require only minor changes to Qt applications by providing alternative implementations of Qt classes where possible. An application using QDS does not have compile-time dependencies on the desktop APIs and no run-time dependencies on the Unix and Linux desktop APIs.
Qt is a comprehensive, object-oriented development framework that enables development of high-performance, cross-platform rich-client and server-side applications. When you implement a program with Qt, you can run it on the X Window System (Unix/X11), Apple Mac OS X, and Microsoft Windows NT/9x/2000/XP by simply compiling the source code for the platform you want. Qt is the basis for the KDE desktop environment, and is also used in numerous commercial applications such as Google Earth, Skype for Linux, and Adobe Photoshop Elements.
Red-Piranha is a search system that can actually learn what you are looking for. It can be used as a Web page, command line, or XML-WebService, so it will work with most languages, including Java, Perl, C#/.NET, and PHP. It includes learning abilities for the Desktop/Internet search functionality. All feedback from the user is stored in (editable) XML and RDF, and is used by the system to improve the quality of searches.
SMS Framework is an Objective C framework for decoding SMS messages in PDU format to objects. It is easily usable in Cocoa and GNUstep environments, and it reduces developer responsibility for decoding messages to extracting the raw messages from the phone. The XCode project file contains three targets: one system wide framework, one framework to include in applications, and a small application for testing the framework.