Firefoxs add-on support makes the browser perfect for anybody unhappy with the performance of features that come preloaded. Download managers are among the more common downloads among those who use Firefox add-ons and they offer many features based on the one you choose. Here are the two most well-known managers, and best of all, theyre free!

DownThemAll
Powerful and easy to use, DownThemAll is completed integrated into Firefox and adds a number of features. Download multiple files with one click, downloading images off of a webpage with ease, autonaming of files and the use of directories so download stay organized. DownThemAll also optimizes download speed by splitting into pieces and claims to increase speeds by up to 400.

FlashGot
Does some of what DownThemAll does but allows for greater control in what is downloaded. Allows easy downloading of multiple files, increases download speeds. FlashGot also specializes in downloading FLV files (YouTube and many other streaming websites) a breeze. If you plan on downloading single, massive files and worry about your downloads failing, FlashGot is a good option. Its often able to salvage a download if your connection dies mid way. FlashGot works in conjunction with DownThemAll; using them together proves very successful/