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.
cproto generates function prototypes for functions defined in the specified C source files to the standard output. The function definitions may be in K&R or ANSI C style, or in the lint library form. cproto can also convert function definitions in the specified files from the K&R style to the ANSI C style.
Styx is a scanner/parser generator designed to address some shortcomings of the traditional lex/yacc combination. It has unique features like automatic derivation of depth grammar, production of the derivation tree, including it's C interface, preservation of full source information, pretty printing to faciliate source-source translation, and persistence to aid rapid interpreter writing. It also supports reentrancy. Styx works well under several different OSes, including serveral Unixes, DOS, and Windows.
The libjit library implements just-in-time compilation functionality. Unlike other JITs, this one is designed to be independent of any particular virtual machine bytecode format or language. Currently, libjit is used as the JIT backend for the DotGNU Portable.NET project (in addition to its default CVM backend). However, the hope is that other Free Software projects can use this library rather than spending large amounts of time writing their own JIT from scratch.
Aubit 4GL compiler is a programming language based on (and compatible with) Informix-4GL. It provides an easy way to generate screen/form based programs, since statements for handling Windows, Forms, Menus, SQL, and similar are built-in. With support for SQL statements forming an intrinsic part of the language, it's especially suitable for developing database-oriented applications. Database connectivity is provided for PostgreSQL, MySQL, Informix, and others via ODBC. It supports both ncurses (console mode) and GTK+ (GUI mode) output.