Allegro is a multi-platform game library for C/C++ developers that provides many functions for graphics, sounds, player input (keyboard, mouse, and joystick), and timers. It also provides fixed and floating point mathematical functions, 3D functions, file management functions, compressed datafile, and a GUI.
BRL-CAD is a powerful constructive solid geometry solid modeling system that includes an interactive geometry editor, ray-tracing support for rendering and geometric analysis, path-tracing for realistic image synthesis, network distributed framebuffer support, and image and signal-processing tools.
Cactus is a general, modular, parallel environment for solving systems of partial differential equations. The code has been developed over many years by a large international collaboration of numerical relativity and computational science research groups and can be used to provide a portable platform for solving any system of partial differential equations.
Calc is arbitrary precision arithmetic system that uses a C-like language. It's useful as a calculator, an algorithm prototype, and as a mathematical research tool. More importantly, calc provides a machine-independent means of computation. Calc comes with a rich set of builtin mathematical and programmatic functions.
CodeBase is a high-speed xBASE compatible database engine for C/C++, Visual Basic, Delphi & Java programmers. You can use CodeBase to write high performance database applications that are multi-user compatible with FoxPro, dBASE and Clipper, create anything from a Java applet to a full-blown Windows database application to a simple DOS utility, write scalable applications that can be deployed as single-user, multi-user or client/server, all without changing any of your source code, and port your applications to Windows, DOS, UNIX, OS/2, and Macintosh. There's a free 30-Day Test Drive option available. CodeBase is available for every major operating system including Windows XP, 2000, 9x, NT, CE, DOS, OS/2, Macintosh, and a variety of Linux and UNIX platforms including Solaris, SunOS, HP/UX, AIX, SCO, and others.
CodeGuide is a lean and fast IDE for Java and JavaServerPages. It features on-the-fly error checking, incremental background ("instant") compilation, powerful refactoring capabilities, and support for generic types. A visual debugger with on-the-fly class replacement (HotSwap) is also included.
Racket (formerly PLT Scheme) is a programming language suitable for implementation tasks ranging from scripting to application development, including GUIs, Web services, etc. It includes the DrRacket programming environment, a virtual machine with a just-in-time compiler, tools for creating stand-alone executables, the Racket Web server, extensive libraries, documentation for both beginners and experts, and more. It supports the creation of new programming languages through a rich, expressive syntax system. Example languages include Typed Racket, ACL2, FrTime, and Lazy Racket.
Java Development Environment for Emacs (JDEE) is an Emacs-based integrated development environment (IDE) for developing Java applications and applets. Features include multiple code browsers, a JPDA-based debugger, method and field completion, template-based and procedure-based code generation, Java source code interpreter, context-sensitive help, and more.