NIMSpro

Current release versions of PHP include three server side engine options
for Windows platforms: CGI, FastCGI, and ISAPI. The FastCGI option for
Windows is unstable, causes hangs, and runs at extremely high CPU
utilization.

DO NOT USE the FastCGI option for NIMSpro(tm)! We have confirmed the bugs
in PHP's FastCGI engine will occur when running large numbers of users or
hosting on a medium to slow server.

Both the regular CGI and ISAPI engines work well and are rock solid for
hosting NIMSpro(tm). We currently use the CGI engine on our Unix/Linux
Internet servers and the ISAPI DLL on our Windows servers used in
classrooms and on LANs. There are some security notices you can find that
discuss the pros and cons of using CGI vs. ISAPI on Internet servers, but
this has nothing to do with NIMSpro(tm) and is well outside of the scope.

Bottom Line: Do NOT use FastCGI!

p.s. One pesky little thing that might be helpful to know about ISAPI on
Windows IIS. When using IIS on WindowsXP Pro and installing the ISAPI dll,
there is a place to indicate the file path to the ISAPI.DLL file. It has a
browse button that seems to work fine... only it doesn't. The path will not
accept long file names. So if you install PHP in the default c:\php, you're
fine. But if you install PHP in c:\Program Files\PHP or something like, not
so much. The solution is simple: c:\Progra~1\PHP.