Which web servers are supporting PHP?

PHP is truly cross-platform. It runs on the Windows operating system; most versions of Unix, including Linux; and Macintosh OS X.

Support is provided for a range of Web servers including Apache (itself open-source and cross-platform), Microsoft Internet Information Server, WebSite Pro, the iPlanet Web Server, and Microsoft’s Personal Web Server. The latter is useful if you want to test your scripts offline on a Windows machine, although Apache can also be run on Windows.