Mojo is now open source!

Lichtso•about 2 hours ago

Technically soruce available now with the promise of accepting contributions (thus becoming fully open source) early next year. But since it is an Apache 2 license (like the rest of the LLVM project) you are already allowed to fork and contribute to your own fork right now, just no upstreaming.

For many the closed source nature of the compiler was a knock-out criterion. We will see if Mojo can gain traction now or if it has missed its window of opportunity.

cube2222•about 1 hour ago

It’s open source under the Apache 2 license, not source available.

Accepting contributions is not required to be open source.

SQLite doesn’t accept contributions from random people either [0] (though you could argue being public domain isn’t being open source).

Anyway, this is great, I was waiting for this to take the language for a spin! Congrats to the Mojo team!

[0]: https://simonwillison.net/2025/Dec/29/copyright-release/

fluffybucktsnek•about 1 hour ago

Technically, the criteria for open source is freedom to freely distribute and modify the source code, not to upstream changes. That's a different for thing.

https://opensource.org/osd

melodyogonna•about 2 hours ago

Related post with relevant pr: https://news.ycombinator.com/item?id=49347777

totalperspectiv•about 2 hours ago

This is really exciting. I've been using Mojo off and on for side projects over the last two years.

(copying from some previous Mojo threads) It's got an ownership system adjacent to Rust, comptime similar to Zig, and a first class dependent type system. Even more exciting, is that uses LLVM (to the best of my understanding) in some novel ways and for more optimizations.

dlahoda•16 minutes ago

Hm, in docs they say that dependent type system is not first class seems.

Is it even dependent? More like refinement types, which seems will be in Rust too.Also HN recently mentioned Rust building similar llvm based integration with GPU.

But compared with Python, Julia, Matlab, R, Rust, C, C++ - Mojo feel relief for working with numerics.

ChrisArchitect•about 2 hours ago

Mojo 1.0

https://news.ycombinator.com/item?id=49261128

Mojo is now open source!

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