Vhost

If you're running Squid to cache your website, you can use an htaccess file to control what kind of files should be cached, and for how long.

You want your website to be as safe as possible. So you'll typically want Open Basedir and Safe Mode to be on. When you're in a shared hosting environment, you'll find that any server administrator with a good sense of security will also have these restrictions in place. However security pretty much always limits functionality and this case is no different. Because what if you are caged in a restricted environment, and you would still like to use shared libraries like the ones provided by PEAR?

I ran across php value, php flag, php admin value and php admin flag in a couple of .htaccess files, and I've used them sometimes as well by just pasting an example, but I've never really understood why there was such a great diversity. Couldn't php_setting X Y just handle it, and if not, what do the admin, value and flag attributes mean?