Note: AdBlock Ultimate is no longer under development and the developer provides no support for it.
AdBlock Ultimate is a free extension that blocks ads and malicious domains known to spread malware, and disables tracking. It includes a few extensive filters that offer decent protection against annoying, flashy ads, YouTube commercials, and more. Unlike other adblockers, it doesn't have a whitelist for websites, advertisers, or ad networks to show you unwanted ads. Blocking ads will speed up your website load speed, and will decrease CPU and memory usage.