If you’re coding in PHP a lot, PHPXref is one of the coolest tools available. It allows you to browse large portions of source code, and find where functions, variables and constants are defined and referenced.
As the PHPXref of WordPress I used to use isn’t available anymore, I decided a couple of weeks ago to build my own WordPress PHPXref, which you can find at xref.yoast.com.
I’ve made a video of how to use it, as it might not be so obvious at first sight:
If you think you’d like to use it but have questions left, feel free to ask, of course!