Ficl is an acronym for "Forth Inspired Command Language".

• It typically takes under 2 hours to port to a new platform.
• Ficl is written in strict ANSI C.
• Ficl can run natively on 32- and 64-bit processors.

A fully featured Win32 console version takes less than 100K of memory, and a minimal version is less than half that. Where most Forths view themselves as the center of the system and expect the rest of the system to be coded in Forth, Ficl acts as a component of your program. It is easy to export code written in C or ASM to Ficl (in the style of TCL), or to invoke Ficl code from a compiled module. Thanks to its "switch-threaded" virtual machine design, Ficl 4 is faster than ever—about 3x the speed of Ficl 3. Ficl also features blindingly fast "just in time" compiling, removing the "compile" step from the usual compile-debug-edit iterative debugging cycle. Ficl is an implementation of the FORTH language, a language providing a wide range of standard programming language features:

• Integer and floating-point numbers, with a rich set of operators.
• Arrays.
• File I/O.
• Flow control (if/then/else and many looping structures).
• Subroutines with named arguments.
• Language extensibility.
• Powerful code pre-processing features.

Ficl conforms to the 1994 ANSI Standard for FORTH (DPANS94). See ANS Required Information for more detail. Ficl is extensible both at compile-time and at run-time. You can add new script functions, new native functions, even new control structures. Ficl's flexible OOP library can be used to wrap data structures or classes of the host system without altering them. (And remember how we said Ficl was extensible? Ficl's object-oriented programming extensions are written in Ficl.) Ficl can be used interactively, like most other FORTHs, Python, and Smalltalk. You can inspect data, run commands, or even define new commands, all on a running Ficl VM. Ficl also has a built-in script debugger that allows you to step through Ficl code as it is executed. Ficl is designed to work in RAM based and ROM code / RAM data environments. Ficl is reentrant and thread-safe. After initialization, it does not write to any global data. The Ficl licence is a BSD-style license, requiring only that you document that you are using Ficl. There are no licensing costs for using Ficl.

Ficl 4.0 features a major engine rewrite. Previous versions of Ficl stored compiled words as an array of pointers to data structure; Ficl 4.0 adds "instructions", and changes over to mostly using a "switch-threaded" model. The result? Ficl 4.0 is approximately three times as fast as Ficl 3.03.

Ficl 4.0 also adds the ability to store the "softcore" words as LZ77 compressed text. Decompression is so quick as to be nearly unmeasurable (0.00384 seconds on a 750MHz AMD Duron-based machine). And even with the runtime decompressor, the resulting Ficl executable is over 13k smaller!

Another new feature: Ficl 4.0 can take advantage of native support for double-word math. If your platform supports it, set the preprocessor symbol FICL_HAVE_NATIVE_2INTEGER to 1, and create typedefs for ficl2Integer and ficl2Unsigned.

Ficl 4.0 also features a retooled API, and a redesigned directory tree. The API is now far more consistent. But for those of you who are upgrading from Ficl 3.03 or before, you can enable API backwards compatibility by turning on the compile-time flag FICL_WANT_COMPATIBILITY.

Ficl 4.0 also extends support every kind of local and global value imaginable. Every values can individually be local or global, single-cell or double-cell, and integer or floating-point. And TO always does the right thing.

If you're using Ficl under Windows, you'll be happy to know that there's a brand-new build process. The Ficl build process now builds Ficl as

• a static library (.LIB),
• a dynamic library (.DLL, with a .LIB import library), and
• a standalone executable (.EXE).

Finally, Ficl 4.0 adds a contrib directory, a repository for user-contributed code that isn't part of the standard Ficl release. The only package there right now is XClasses, a Python-based IDL that generates the definition files for C++-based classes, the equivalent Ficl classes, and code to allow the Ficl classes to call the C++ methods. Using XClasses you can write your class once, and use it immediately from both C++ and Ficl. You can download Ficl from the Ficl download page at Sourceforge.