a clean, elegant, and pragmatic dialect of Forth
work on refactoring/cleaning up takawiri
takawiri: string previews working
revert part of the dev-files.c changes



You can also use your local clone with git send-email.

      d8888b. d88888b d888888b d8888b.  .d88b.
      88  `8D 88'     `~~88~~' 88  `8D .8P  Y8.
      88oobY' 88ooooo    88    88oobY' 88    88
      88`8b   88~~~~~    88    88`8b   88    88
      88 `88. 88.        88    88 `88. `8b  d8'
      88   YD Y88888P    YP    88   YD  `Y88P'

Retro is a modern, pragmatic Forth drawing influences from many sources. It's clean, elegant, tiny, easy to grasp, and adaptable to many tasks.


  • Open Source (ISC License)
  • Portable (runs on a MISC-style virtual machine)
  • Small source & binaries
  • Builds into a single, self contained binary
  • Sources in literate format, using a Markdown variant

#Quick Start

For most systems (FreeBSD, NetBSD, OpenBSD, macOS, Linux):


You will need a standard C compiler and make.


Binaries will be placed in the bin directory.

The primary executable is retro. This is used for running the examples and the Atua (gopher) & Casket (http) servers that power retroforth.org.

The retro executable embeds the image into the binary, making it trivial to copy and deploy.

This interface layer also extends the language with many new words and vocabularies, adds scripting, files, floating point, and more.

The retro executable can handle a variety of command line arguments which are covered in the manpage, but the most common ones are:


Starts the listener, a basic REPL for interactive use.

retro filename

This will run the code in the specified file, then exit. This is also used to run programs as shell-type scripts using a header line like #!/usr/bin/env retro.

retro -i -f filename

This will run the code in the specified file, then start the listener.

#Literate Sources

Source files for use with retro are written with code in fenced blocks:

commentary here

code here

Anything outside the fenced blocks will be ignored.


The primary documentation is in RETRO-Book.md (and the formatted epub.) Additional notes can be found in the doc directory.

#Alternative Implementations

In addition to the C and Python implementations, this source tree includes additional implementations in C#, Nim, JavaScript, and Pascal. These are not as well tested or as feature complete as the main implementations, but are provided for your use if the standard implementations will not suffice.

#Learn More

Visit http(s)://retroforth.org to learn more and follow along with development.


I have a Patreon at https://www.patreon.com/_crc for those that want to financially support development. All funds raised via Pateron are put into development related expenses (server expenses, app store fees, hardware).

Thanks go out to my current and past patrons:

  • Kiyoshi YONEDA
  • Krinkleneck
  • Rick Carlino
  • Scott McCallum
  • Bartels Jon Randy
  • Nuno
  • Eli
  • Brad S
  • Tobias Ammann
  • oneearedrabbit
  • Octavio Turra