php-eaccelerator, php-mbstring, php-ncurses, php-snmp These packages seemed to be missing from your CentOS 4.3 guide. Maybe it was on purpose but having them fixed an issue with one of my sites. KEEP UP THE GOOD WORK!
Eaccelerator - http://eaccelerator.net/ Mbstring - http://us3.php.net/mbstring Ncurses - http://us2.php.net/ncurses SNMP - http://www.guanotronic.com/~serge/phpsnmp.php3
But that is more stuff for you webserver, not for the ISPCOnfig one? The only thing I could think of would be eaccelerator if the server seems to be too slow on the admininterface or mbstring.... is phpsnmp still developed? Seems not? But to use it for your customers you can install them on your own on your serverconfig?
Your right its for your server. I posted it in the Linux forums and not ISPConfig forums because of that. The only reason I mentioned it is because without these installed I was not able to test some CMS apps for some clients because these modules were not installed (i am not sure which one caused the problem.)
Have a look here: http://www.ipersec.com/index.php?q=en/bench_ea_vs_apc We're using eaccelerator on HowtoForge and are quite satisfied.