When 7.4 was released, with FFI now available, I had the crazy idea to make a cli text editor in PHP[1] (based on kilo[2], and since 8 has come out, with the addition of the PHPToken class, highlighting PHP with PHP has gotten easier.

1. https://git.timshomepage.net/timw4mail/php-kilo 2. https://viewsourcecode.org/snaptoken/kilo/