PHP needs a server for you to be able to view the site through a browser. You can download Apache which can run on windows or *nix, or if you have an windows NT-based machine (ie NT, 2K or XP) you can run IIS or if you have a 9x based machine (95, 98, ME) then you can install PWS. All of these will run PHP.
Dammit! 1 minute too late :rolleyes: