Colin O’Dell, Lead Web developer at Unleashed Technologies, is an active member in the PHP community. He maintains multiple open-source projects, including the PHP League's CommonMark project, which has been installed over 793,000 times across the world.
Here is the full list of PHP League libraries used on the website:
The PHP League’s CommonMark project is a PHP-based Markdown parser, created by O’Dell, which supports the full CommonMark spec. It is based on the CommonMark JS reference implementation by John MacFarlane.