Fennel – a Lisp syntax for Lua #Programming

Fennel is a programming language that brings together the speed, simplicity, and reach of Lua with the flexibility of a lisp syntax and macro system.

  • Full Lua compatibility: Easily call any Lua function or library from Fennel and vice-versa.
  • Zero overhead: Compiled code should be just as or more efficient than hand-written Lua.
  • Compile-time macros: Ship compiled code with no runtime dependency on Fennel.
  • Embeddable: Fennel is a one-file library as well as an executable. Embed it in other programs to support runtime extensibility and interactive development.

Anywhere you can run Lua code, you can run Fennel code.

Read more on the Fennel website.

Fennel’s repository is on Sourcehut. There is also a wiki for collecting ideas.


Fennel is copyright © 2016-2021 Calvin Rose and contributors and is released under the MIT/X11 license.


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1 Comment

  1. Thanks for the shout-out! I’m the lead developer of Fennel.

    I’ve used it for some hardware hacks using an ESP8266 to run an IRC bot based on nodeMCU: https://git.sr.ht/~technomancy/pengbot/tree/micropeng/ Some other folks have gotten it running on an ESP32 as well, which is an even better fit. Figure those might be interesting to other Adafruit blog readers.

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