Not really the same because you can say "We don't support IE version x" and be done with it. There are much more variables at play in a server setup: PHP, MySQL

Not really the same because you can say "We don't support IE version x" and be done with it. There are much more variables at play in a server setup: PHP, MySQL, web server, OS etc.. Each of these can be running different versions and each instance (of PHP for example) can be configured completely differently from the next.