The argument against Mojo is that it replaces CUDA (that you get for free with the hardware) with something that you need to license.

By itself, that's not so bad. Plenty of "buy, don't build" choices out there.

However, every other would-be Mojo user also knowns that. And they don't want to build on top of an ecosystem that's not fully open.

Why don't Mathematica/MATLAB have pytorch-style DL ecosystems? Because nobody in their right mind would contribute for free to a platform owned by Wolfram Research or Mathworks.

I'm hopeful that Modular can navigate this by opening up their stack.

I really want to like Mojo but you nailed what gives me pause. Not to take an anecdotal example of Polars too far beyond, but I get the sense the current gravity in Python for net new stuff that needs to be written outside Python (obviously a ton of highly performant numpy/scipy/pytorch ecosystem stuff aside) is for it to be written in Rust when necessary.

Not an expert, but though I wouldn't be surprised if Mojo ends up being a better language than Rust for the use case we're discussing, I'm not confident it will ever catch up to Rust in ecosystem and escape velocity as a sane general purpose compiled systems language. It really does feel like Rust has replaced C++ for net new buildouts that would've previously needed its power.

> The argument against Mojo is that it replaces CUDA (that you get for free with the hardware) with something that you need to license.

You realize that CUDA isn't open source or planned to be open source in the future, right?

Meanwhile parts of Mojo are already open source with the rest expected to be opened up next year.