FreeForth is a small and fast interactive compiler composed of an extensible set of macros generating inline compact i386 native code, including floating-point instructions, and an easy interface to Linux and Windows dynamic libraries. It uses two stacks to pass subroutines arguments and results separately from return addresses, like other Forth dialects, but unlike them, it is a simpler pure compiler (without an interpreter) offering interactivity through "anonymous" subroutines which are executed by their closing ";" macro. FreeForth is fully documented by 100K of interactive online help. Since its first release in 2006, it has been used every day for cross-development of realtime industrial applications embedded in microcontrollers, and for PC-controlled manufacturing test benches. The FreeForth distribution includes an interactive incremental assembler for the MSP430 microcontroller family.
Minimac is a minimalist, general purpose text macro processor. Its simplicity should make it particularly well suited as a front end preprocessor for little language compilers. It is meant to be simpler to use than m4. It uses an explicit argument stack, and user functions are defined by concatenation (similar to the Forth language). Macro expansion is delayed to the last possible moment. The software is currently in alpha release.
Michael4 is a Forth-like language implemented for the 64-bit Alpha Linux platform. It was tested on gentoo Alpha. It differs slightly from normal Forths in that you can call words that are not yet defined and they are automatically stubbed if the source code file doesn't exist for them.
amforth is an extendible command interpreter for the Atmel AVR ATmega microcontroller family. It has a turnkey feature for embedded use as well. It does not depend on a host application. The command language is an almost compatible ANS94 forth with extensions. It needs less than 8KB code memory for the base system. It is written in assembly language and forth itself.