Rustlang

Rust is a systems programming language built for performance, safety, and concurrency without a garbage collector. Its ownership model, enforced at compile time, guarantees memory safety and prevents data races. You get C-level speed with modern type-system guardrails: pattern matching, algebraic data types, traits, and a strict borrow checker that catches entire classes of bugs before they run. Designed for low-level work — operating systems, browsers, embedded devices, performance-critical services — Rust now ships in the Linux kernel and across Big Tech production stacks. Open-source, first released in 2015 and stewarded by the Rust Foundation. Steep learning curve, durable payoff.

Rewrite Bun in Rust (github.com) (via).

From Jarred Sumner on the PR:

Blog post with details coming soon.

It passes Bun's pre-existing test suite on all platforms (and fixes several memory leaks and flaky tests), the binary size shrinks by 3 MB - 8 MB, the benchmarks are between neutral and faster - and most importantly, we now have compiler-assisted tools for catching & preventing memory bugs, which have costed the team an enormous amount of development & debugging time over the years.

The codebase is otherwise largely the same. The same architecture, the same data structures. Bun still uses few 3rd party libraries. No async rust.

To try this, run:

bun upgrade --canary

Please do file issues if you run into any. If this thread gets crazy I will lock it.

Note:

  • Still some optimization work to do before this lands in non-canary version.

  • Still some cleanup work to do (which will come in a series of follow-up PRs)

Ambitious.

LLMs + a well thought out test suite they can verify against can go a long way.

Posted 2026-05-14 | #anthropic #rustlang #opensource