Hans Halverson:

Brimstone is a JavaScript engine written from scratch in Rust, aiming to have full support for the JavaScript language.

Brimstone is a work in progress but already supports almost all of the JavaScript language (>97% of the ECMAScript language in test262). Not ready for use in production.

Brimstone features:

• Bytecode VM, heavily inspired by the design of V8’s Ignition
• Compacting garbage collector, written in very unsafe Rust
• Custom RegExp engine
• Custom parser
• Almost all builtin objects and functions implemented to spec

I love it when a near complete project just appears out of nowhere.

aapoalas on Lobsters:

As a fellow JavaScript engine developer, this was a really humbling project to stumble upon recently: effectively feature complete, double the performance of Boa which is already double the performance of the engine I work on, and done by a single person in the span of quite exactly 3 years (started November 19th of 2022). The engine I work on had its first commit a few months before that, although actual development started only in the summer of 2023.

Brimstone appears to be quite an impressive effort for a solo developer. The other project in the space that I’ve been watching is Boa. Boa had a notable release last month that included a bunch of improvements, and some significant performance gains.

From a quick glance over the API it looks like Boa has a more developed story for Rust⇿JavaScript bindings.