Skip to main content

RetroForth is a modern, pragmatic Forth

Project description

Retro: A Modern, Pragmatic Forth

RETRO is a modern, pragmatic Forth drawing influences from many sources. It's clean, elegant, tiny, and easy to grasp and adapt to various uses.


  • Open Source (ISC License)
  • Portable (runs on a MISC-style virtual machine)
  • Small source & binaries
  • Builds into a single, self contained binary for easy deployment
  • 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

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, file i/o, gopher, and floating point math support.

The retro executable can handle a variety of command line arguments:

retro -i

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.

retro -h

Displays a summary of the command line arguments.

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 (and the formatted RETRO-Book.html.) 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#, 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.


I have a Patreon at 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

Project details

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

retroforth-2021.1.tar.gz (24.8 kB view hashes)

Uploaded source

Built Distribution

retroforth-2021.1-py3-none-any.whl (24.8 kB view hashes)

Uploaded py3

Supported by

AWS AWS Cloud computing Datadog Datadog Monitoring Facebook / Instagram Facebook / Instagram PSF Sponsor Fastly Fastly CDN Google Google Object Storage and Download Analytics Huawei Huawei PSF Sponsor Microsoft Microsoft PSF Sponsor NVIDIA NVIDIA PSF Sponsor Pingdom Pingdom Monitoring Salesforce Salesforce PSF Sponsor Sentry Sentry Error logging StatusPage StatusPage Status page