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.
| Tags | Software Development Libraries Code Generators Compilers |
|---|---|
| Licenses | LGPL |
| Operating Systems | Windows MS-DOS POSIX Linux Windows Windows Windows Mac OS X BSD |
| Implementation | Forth C |
Recent releases


Changes: A preprocessor was added. The multitasking environment was rewritten. Several ANS floating point bugs were fixed. Another floating point environment, called Zen float, was added. The Linux version now supports shared libraries. More complex patches are supported. Various other additions and fixes were made to the libraries and examples.


Changes: Several bugs in the floating point library were fixed. The circular ring buffer library was rewritten. Many FSL and forth200x words were added to the library. The return value of "OPEN" was standardized. "AS" was removed. "ERROR?" and "BUFFER:" were added. The editor can now export text files. A classic "Startrek" program was added to the examples. New sections were added to the Development Guide.


Changes: A floating point emulation library was added, providing most words of the FLOATING and FLOATING EXT wordsets. A few bugs were fixed in the "mixed" library.


Changes: A default 4tH directory can be defined by setting an environment variable. Support for creating custom 4tH implementations was added. The multitasking environment is scriptable now. The library files concerning ANS Core Extensions, table searching, and interpretation have been rewritten or replaced.


Changes: The words C and OFFSET have been added. The multitasking environment has been fully integrated in the source tree.