O’Reillynet posted an article about using PHP in Project Builder under Mac OSX:
Apple provides a powerful set of developer tools with Mac OS X. Originally developed by NeXT for programmers working with Objective-C, the tools have since evolved for use with a wide range of source languages, including Java, C++, and AppleScript. The Mac OS X developer tools package also includes the system header files and a C compiler, so it is an essential addition for anyone who wants a complete BSD Unix environment. At the heart of Mac OS X’s developer tools is a full-featured text editor and IDE called Project Builder. [via RootPrompt.org]