Fair question, and agreed we should make this clearer on the site.

We like Octave a lot, but the reason we started fresh is architectural: RunMat is a new runtime written in Rust with a design centered on aggressive fusion and CPU/GPU execution. That’s not a small feature you bolt onto an older interpreter; it changes the core execution model, dataflow, and how you represent/optimize array programs.

Could you add a JIT to Octave? Maybe in theory, but in practice you’d still be fighting the existing stack and end up with a very long, risky rewrite inside a mature codebase. Starting clean let us move fast (first release in August, Fusion landed last month, ~250 built-ins already) and build toward things that depend on the new engine.

This isn’t a knock on Octave, it’s just a different goal: Octave prioritizes broad compatibility and maturity; we’re prioritizing a modern, high-performance runtime for math workloads.