Eaccelerator is a PHP accelerator/encoder/caching utility that is based off of the old mmcache (which is no longer being maintained).
What Eaccelerator does is: it caches your PHP scripts so that the database is no longer being queried everytime someone needs a script. This is particularly useful for large forums, but pretty much anyone can benefit from it. Since these scripts are cached, you’ll notice a decrease in memory use and server load.
Continue reading PHP optimization How-To: Installing Eaccelerator
