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.
SWIG is a software development tool that connects programs written in C and C++ with a variety of high-level programming languages. SWIG is primarily used with common scripting languages such as Perl, PHP, Python, Tcl/Tk, and Ruby, however the list of supported languages also includes non-scripting languages such as C#, Common Lisp (CLISP, Allegro CL, UFFI), Java, Modula-3, OCAML, Octave, and R. Also several interpreted and compiled Scheme implementations (Guile, MzScheme, Chicken) are supported. SWIG is most commonly used to create high-level interpreted or compiled programming environments, user interfaces, and as a tool for testing and prototyping C/C++ software. SWIG can also export its parse tree in the form of XML and Lisp s-expressions.
GNU `tar' saves many files together into a single tape or disk archive, and can restore individual files from the archive. It includes multivolume support, the ability to archive sparse files, automatic archive compression/decompression, remote archives and special features that allow `tar' to be used for incremental and full backups. It also includes `rmt', the remote tape server (the `mt' tape drive control program is in GNU `cpio').
XBoard is a graphical chessboard for X that can serve as a user interface to play against any of a variety of chess engines that run on your local machine, or against human or computer opponents on an Internet chess server. XBoard can also be used by itself to read and write game files in PGN (portable game notation). WinBoard is a port of XBoard to Microsoft Win32.
GNU Radius is a RADIUS server and an accompanying set of monitoring utilities. It features MySQL and PostgreSQL interfaces for authentication and/or logging (the ODBC interface allows you to use almost any existing DBMS for that purpose), the ability to rewrite RADIUS requests from various NASs to normalize them to a more understandable format, and the ability to completely customize the behavior of RADIUS authentication and accounting based on NAS and user attributes.
Shrimp is a visual workflow to the RenderMan shader creation, written on top of the FLTK2 library and using OpenGL for scene display. It will let you connect blocks of functions in a visual fashion much like an electronic CAD package, and it will create a preview from the connected shaders (surface, displacement, light, etc). Once satisfied, you can export the resulting shaders and use them in your 3D scenes using any RenderMan compliant engine, such as Aqsis, 3Delight, or PRMan.