Fennel

Fennel is a programming language that brings together the simplicity, speed, 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 efficient as 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.

• video game dev
• window managers
• web servers
• data bases
• web browsers
• cheap microcontrollers

Install it now!

 ;; Sample: read the state of the keyboard and move the player accordingly (local dirs {:up [0 -1] :down [0 1] :left [-1 0] :right [1 0]}) (each [key [dx dy] (pairs dirs)] (when (love.keyboard.isDown key) (let [[px py] player x (+ px (* dx player.speed dt)) y (+ py (* dy player.speed dt))] (world:move player x y)))) 

I don't feel like installing it right now!

Fine, you can use Fennel right here without installing anything:

Curious about how a piece of code compiles? See for yourself with a side-by-side view how Fennel turns into Lua and vice-versa.

Documentation

• The Setup Guide will help you install things.
• The Tutorial teaches you the basics of the language.
• The Rationale explains the reasoning why Fennel was created.
• The Lua Primer will catch you up if you don't already know Lua.
• The Reference lists out all built-in forms and what they're for.
• The Fennel from Clojure guide helps if you have a background in Clojure.
• The Style Guide advises on how to write clear and concise code.
• The Macro Guide explains metaprogramming with macros.
• The API Listing explains how to embed Fennel into a Lua program.
• The Changelog describes how Fennel has evolved with time.
• The Wiki has all kinds of things in it.

Looking for other versions? Docs are generated for:

• v1.5.3
• v1.5.2
• v1.5.1
• v1.5.0
• v1.4.2
• v1.4.1
• v1.4.0
• v1.3.1
• v1.3.0
• v1.2.1
• v1.2.0
• v1.1.0
• v1.0.0
• v0.10.0
• v0.9.2
• v0.9.1
• v0.9.0
• v0.8.1
• v0.8.0
• v0.7.0
• v0.6.0
• v0.5.0
• v0.4.3
• v0.4.2
• v0.4.1
• v0.4.0
• v0.3.2
• v0.3.1
• v0.3.0
• v0.2.1
• v0.2.0
• v0.1.1
• v0.1.0

Development

We track bug reports, enhancement ideas, and other issues on dev.fennel-lang.org .

Fennel's repository is on Sourcehut.

See the security page for details about reporting security issues.

Community

• The #fennel channel on Libera.chat is where most of the discussion happens. It is also bridged to Matrix.
• The mailing list hosts slower-paced discussion.
• The Fennel User Group meets on video chat on the third Saturday of each month at 10:00 US Pacific/17:00 UTC.
• The FennelConf site hosts talks from previous years.
• The community surveys collect data about Fennel users.
• The wiki has all sorts of community-contributed content including the list of codebases and the cookbook.

All community interactions are subject to the code of conduct.