I use Turck MMCache as my opcode accelerator. An accelerator saves your compiled PHP scripts for reuse, typically speeding up your web server by 50-200%.

Turck MMCache is fast (having won several benchmarking contests), open source, runs on all platforms I use (Windows, Linux, Solaris) and has a generic shared memory cache that your PHP code can use for storing HTML snippets and serialized objects. Strangely enough, I notice that Nick Lindridge, author of the IonCube Accelerator is one of the code contributors; this is weird as IonCube is a commercial competitor.

There hasn't been a release of Turck MMCache for a while. If you want a binary version that runs on Windows, you need to compile your own. That's bothersome; not everyone has the appropriate compiler tools or the know-how. Fortunately, the administrator of localfoo.info (I'm not sure of his name, it's a german web-site) has compiled working versions: Turck MMCache 2.4.7-CVS for PHP 4.3.8 and PHP 5.0.0.

I'm testing on PHP 4.3.8 now. Seems to work well. I haven't tried 5.0.0 yet.

PS: How do you know that you're a geek? When you find names like ADOdb and Turck MMCache exciting.