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Mojo is now open source

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Re: Mojo is now open source

#2
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.

Re: Mojo is now open source

#3
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.

Re: Mojo is now open source

#6
post #2

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…

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

Re: Mojo is now open source

#8
post #2

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’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/

Re: Mojo is now open source

#9

Such an exciting time for Mojo, I don't think people realize just yet the innovation being brought to fore here.

The innovative potential of Mojo would be constrained to relatively niche and senior dev circles until they get a Windows release, which probably won't happen anytime soon. Python keeps the throne for now.

Re: Mojo is now open source

#10
post #9

Such an exciting time for Mojo, I don't think people realize just yet the innovation being brought to fore here.

The innovative potential of Mojo would be constrained to relatively niche and senior dev circles until they get a Windows release, which probably won't happen anytime soon. Python keeps the throne for now.

They announced a partnership with Microsoft today.
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