PHPXref is a developer tool that's designed to ease the process of working on large PHP projects by making it very fast and easy to browse the code documentation along with the code itself.
It works by scanning a project directory and translating the files it finds into readable cross-referenced HTML, simultaneously utilizing comments in the code to produce documentation to accompany it.
The result is a collection of plain HTML files that can be read using any browser, with no supporting software required.
PHPXref has very minimal requirements to run; just having a copy of Perl installed is all you need (and the Windows binary supplies that for you). Getting started requires editing two or three lines in the configuration file and running the program.