I was just reading about mod_pagespeed created by Google and wondered if this can be used successfully with ISPConfig? They claim there is a major increase in speed for page loading times http://googlewebmastercentral.blogspot.com/2010/11/make-your-websites-run-faster.html
Should be no problem. I think you can use it in the global Apache configuration, or otherwise you can use the Apache Directives field in ISPConfig to include the needed directives in your vhost.
I installed it on mine just to see what it does. It actually seemed to slow down the loading of my Roundcube webmail pages. At least initially, anyway. I will test it out during the day and see if there is any noticeable difference. As a side note, using firebug and the pagespeed extension for firefox to analyze my Roundcube webmail pages, it suggested using compression like mod gzip would improve loading some elements by 70% or so. I will now investigate whether mod gzip will have any impact on load.
OK, apparently mod_gzip is for older apache and mod_deflate is used for apache2. Mod_deflate is enabled by default, but i suppose it is only configured to compress certain directories, like a client website /var/www/clientx. So the question now is how to enable compression for other directories like my roundcube directory which is in /usr/share/roundcubemail? My server is set up only as a mailserver currently, and I have the default page pulling up webmail login. So if someone goes to http://webmail.domain.com it goes to the login. I actually have no domains or sites set up other than the default. It is pointed to roundcube by a simple softlink in /var/www/. Code: index.php -> /usr/share/roundcubemail webmail -> /usr/share/roundcubemail I am thinking this is why the pagespeed analysis tells me that compression is not enabled. Because my roundcube directory is outside of the normal path. Now I just need to figure out where to modify that path.