The PHP documentation is written in XML using the Doc Book? DTD. If you would like to contribute to the PHP documentation project, you need to at least know the very basics of XML and Doc Book?.
The XML files are stored on a central server, and can be reached with a CVS client. There are many CVS clients you can use, although we recommend one command line tool or a proven WYSIWYG tool.
You will need more programs and tools to manipulate the XML files and test their content for errors. What tools you need depends on the operating system you use. Linux or some sort of Unix is recommended, although many things in phpdoc work on Windows. You will find more information about the tools you need in the tools section.