[aleem]

I haven't used Parsedown but I am glad things are moving to CommonMark -- it will shift the focus to performance, structure and extensibility instead of struggling with edge cases and Markdown idiosyncrasies.

PHP CommonMark's compliance is very current--CommonMark spec 0.13, Dec 15, 2014 and it will continue to keep up.

It follows the reference implementation very closely, has good support for extensibility and the code is very well structured. It's likely to become the de facto PHP implementation in my opinion.