If you think that your firefox is slow you can try the following tweak to fasten it.
Note:- Try this only if you are an expert.
- Type “about:config” into the address bar
and hit enter.A warning sign will appear, click continue. Scroll to the entry- "network.http.pipelining" - Change the value to "True" by double-clicking it. Scroll to the entry- "network.http.proxy.pipelining" - Change the value to "True" by double-clicking it. Scroll to the entry- "network.http.pipelining.maxrequests" - Change the value to "8" by double-clicking it. Not more than 8, because 8 is the max value allowed. Now, right-click anywhere and select New >> Integer., name it “nglayout.initialpaint.delay” and set its value to “0?. This value is the amount of time the browser waits before it acts on information it receives. Now you might feel the difference.
