Luau Goes Open-Source

When Roblox was created 15 years ago, we chose Lua as the scripting language. Lua was small, fast, easy to embed and learn and opened up enormous possibilities for our developers.

A lot in Roblox was built on Lua including hundreds of thousands of lines of internally-developed code that powers Roblox App and Roblox Studio to this day, and the millions of experiences that developers have created. For many of them, it was the first programming language they’ve learned.

A few years ago, we started looking into how we can evolve Lua to be even faster, have better ergonomics, make it easier to write robust code and to unlock an ecosystem of rich tooling—from better static analysis to IDE integrations.

This is how Luau was born.

Luau is a new language that started from Lua 5.1 and kept evolving while keeping backwards compatibility and preserving the original design goals: simplicity, performance, embeddability.

We’re incredibly grateful for the foundation that Lua has been—it’s been a joy to build on top of! So now we want to give back to the community at large.

Starting today, Luau is no longer an inseparable part of Roblox platform; it’s a separate, open-source language.

Luau is available at and comes with the source code for the language runtime and all associated tooling: compiler, type checker, linter. The code is available to anyone, free of charge, under the terms of MIT License. We’re happy to accept contributions to the language, whether that’s documentation or source code.

The language evolution is driven by an RFC process that is also open to the public.

We are committed to improving Luau going forward—it remains a central piece of technology at Roblox. The team that works on the language keeps growing, and we have lots of ideas! The language will become even faster, even nicer to work with, even more powerful.

We can’t wait to see what we can build, together.