For which languages does it work? The comments in prettify.js are authoritative but the lexer should work on a number of languages including C and friends, Java, Python, Bash, SQL, HTML, XML, CSS, ...

See https://github.com/PHPOffice/PhpSpreadsheet/tree/4.3.1 All the library classes are available in the extension file Library/phpoffice-phpspreadsheet.phar which is ...