How to Contribute to PHP

PHP has powered a huge portion of the web for a long time now. It's launched untold numbers of careers and businesses, and many developers attribute their entire careers to the language. But when we find ourselves wanting to give back, it's not always clear how; sure, PHP is open source, but where do we contribute? How? I've run into that wall before. My immediate issue was that I didn't write C, followed pretty immediately by how overwhelming it felt to learn the entire…