4tH is a Forth compiler with a little difference. Instead of the standard Forth engine it features a conventional compiler. 4tH is a very small compiler that can create bytecode, C-embeddable bytecode, standalone executables, but also works fine as a scripting language. It supports about 95% of the ANS Forth CORE wordset and features conditional compilation, pipes, files, assertions, forward declarations, enumerations, structures, suspended execution, recursion, include files, etc. It comes with an RPN calculator, line editor, preprocessor, compiler, decompiler, C-source generator, a virtual machine, and a multitasking environment.
getmail is intended as a simple, secure, and reliable replacement for fetchmail. It retrieves email (either all messages, or only unread messages) from one or more POP3, SPDS, or IMAP4 servers (with or without SSL) for one or more email accounts, and reliably delivers into qmail-style Maildirs, mboxrd files, or through external MDAs (command deliveries) specified on a per-account basis. getmail also has excellent support for domain (multidrop) mailboxes, including delivering messages to different users or destinations based on the envelope recipient address.
PACT is a self-contained set of tools which support developing and using portable programs, particularly scientific and engineering applications. By defining a single, higher level, standard programming interface, it shields application developers from the plethora of different hardware architectures and operating systems and their non-standard features.
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.
JSBSim is a multi-platform flight dynamics model. The FDM is essentially the physics/math model that defines the movement of an aircraft under the forces and moments applied to it using the various control mechanisms and from the forces of nature. JSBSim has no native graphics. It can be run by itself as a standalone program, taking input from a script file and various aircraft configuration files, or it can be run as an integrated part of a larger flight simulator implementation that includes a visual system. The most notable usage example is the FlightGear simulator. JSBSim models the aerodynamic forces and moments by the classic coefficient buildup method.
Open Watcom consists of the famous Watcom C++ and WATFOR compilers -- now open source. Open Watcom is mainly used for developing embedded, DOS, and ncurses software. Open Watcom includes the C/C++/Fortran IDE from Watcom for DOS and a full set of command-line tools for compilation, including the superb Watcom debugger. Open Watcom emits easy-to-understand errors and warnings when things go wrong. Open Watcom generates small statically linked binaries for Linux, Win32, Win16, OS/2, QNX, NetWare, and MS-DOS real and protected mode, among other targets. However, Open Watcom is still only beta-quality on Linux and BSD. The two most serious issues are imperfect C++ template support and an inability to dynamically link with shared libraries built by GCC. Also, Open Watcom is released under the Sybase Open Watcom Public License, which is considered non-free by most Debian Linux developers. NOTE: Open Watcom binaries for Linux are not available anywhere. You must build it yourself. 1.5 has known build issues on Linux; use version 1.4 or the current daily build instead.