Pasir is like frankenphp, but in Rust. Very promising, but still early in development:
https://github.com/el7cosmos/pasir
Which uses the following Zend API bindings for Rust:
https://github.com/davidcole1340/ext-php-rs
There's also all sorts of interesting experiments, like ngx-php, which basically embeds PHP via Zend API inside an nginx binary: https://github.com/rryqszq4/ngx-php
And workerman, which has a hybrid backend of asio libraries, so you can get pretty fast runtimes: https://github.com/walkor/workerman
replies(2):