Fe is a tiny, embeddable, Lisp-like language implemented in C23.

This version is a refactored and extended version of the beautiful original by rxi.

The language offers the following features:

• Numbers, symbols, strings, pairs, lambdas, and macros
• Lexically scoped variables
• Closures
• Variadic functions
• Mark-and-sweep garbage collector
• Stack traceback on error

The implementation aims to fulfill the following goals:

• Practical for small scripts (extension scripts, configuration files)
• Small memory usage within a fixed-size, caller-allocated arena — no mallocs
• Simple mark-and-sweep garbage collector
• Easy-to-use C API
• Concise, readable, and portable implementation
• Extensible — an extension API allows the core to remain small and stable

• Example scripts and their test expectations
• C API overview
• Language overview
• Implementation overview

Bug reports, pull requests, and questions are welcome.

This program is free software; you can redistribute it and/or modify it under the terms of the MIT license. See LICENSE for details.