I would like to self-nominate Grimoire CSS.
Grimoire CSS is a Rust-powered, all-in-one CSS engine that outputs production-ready styles without bundlers, preprocessors, or postprocessors.
At the core are Spells—simple property=value declarations — and Scrolls, reusable modules with variables and inheritance that let you design entire style systems with ease.
Its language-agnostic parser extracts Spells from any file type (.html, .tsx, .mdx, .txt, you name it) in both filesystem and pure in-memory modes, so you’re never limited by framework or format.
Everything is optimized for peak performance - processing 200,000 classes per second (5× faster and 28× more memory-efficient than Tailwind v4) - while respecting the full CSS cascade, adding vendor prefixes, minifying, deduplicating and much more on the fly.
Available as a standalone binary, Rust crate, or NPM library.
And this is just a glimpse of what Grimoire CSS can do. Visit https://grimoirecss.com to explore its full feature set, including interactive sections for animations, playground, the transmutator, and more.
Thank you! (• ε •)