If you've wanted to contribute something back to PHP but aren't familiar with C (or don't feel comfortable enough with it) Sammy Powers offers another solution. In his latest post he shows you how to contribute to the PHP documentation and update the manual for new features, missing information or fixes to current code examples.
If you've been wanting to contribute to PHP internals, starting with the documentation can be a great entry point; especially because it doesn't require dusting off those old C books from college. But knowing where to start can be tricky since information on how to contribute to the docs is scattered across the internet. This article is a step-by-step guide of how to contribute documentation to the PHP manual.
He starts with the "quick and dirty" way of editing the manual through the edit.php.net site, but points out that it's really only useful for smaller changes, not large documentation updates. The rest of the post shows you how to set up the documentation locally and generate the results to validate your changes. He talks some about the DocBook format they're written in, the build process with the PhD (PHP docs generator) and running the php.net test suite against the changes. This ensures that nothing else has broken on the site in the process.
He shows you where to make your changes, how to generate it from either a skeleton or using the docgen script and submitting the changes back to the repository. There's also a few other random changes to make before committing the files back via SVN and pushing them back upstream. He ends the post talking about the GoPHP7-ext project and how to find extensions that are missing documentation or where it's incomplete (easy thanks to an included "check-missing-docs" file included in the repository).