Tired of configuring Firefox to it’s best performance?
It’s possible to backup your browser settings and add-on settings and it’s also possible to add new settings just in the preferences file since it’s just a *.js file. That means Javascript.

You can find this file on your harddisk:
XP:

C:\Documents and Settings\<username>\Application Data\Mozilla\Firefox\Profiles\<profile ID>\

Vista:

 \Users\<username>\AppData\Roaming\Mozilla\Firefox\Profiles\<profile ID>.default\

Open the prefs.js file with your favorite dev editor.
From here you can make a backup of this file or add new settings, for example:

user_pref("bidi.support", 0);
user_pref("browser.tabs.tabMaxWidth", 100);
user_pref("browser.tabs.tabMinWidth", 50);
user_pref("layout.word_select.eat_space_to_next_word", false);
user_pref("network.http.max-connections", 96);
user_pref("network.http.pipelining", true);
user_pref("network.http.pipelining.maxrequests", 16);
user_pref("network.http.pipelining.ssl", true);
user_pref("network.http.proxy.pipelining", true);
user_pref("nglayout.initialpaint.delay", 50);