Open Source
Whim
The Whim Programming Language
Suffete
Suffete is a standalone PHP type system written in Rust. It provides a representation of PHP types and a type checker. really, a type comparator.
Extension Typst
A PHP extension that embeds the Typst typesetting engine, giving you fast, programmable document generation (PDF, PNG, JPEG, SVG) directly from PHP.
Mago
An extremely fast PHP linter, formatter, and static analyzer, written in Rust.
PSL
PHP Standard Library providing consistent, predictable functions with strong typing and immutable data structures.
CEL-PHP
Common Expression Language implementation in pure PHP. Secure expression evaluation for configuration and rules engines.