While not exactly making earth-shattering changes, this Firefox extension takes your current version of Download Manager and offers small upgrades to bring it up a notch.
Download Manager Tweak gives you the option of viewing Download Manager in a separate window, as a sidebar, or as an extra tab. We especially liked the sidebar option so that you can keep an eye on your download progress while browsing at the same time. You can select which toolbar buttons you want to be visible, such as the Launch or Options button. Everything worked without any problems, and our downloads went off without a hitch. But beware: Clicking the Clean Up button will wipe the entire download history at once.
Though the changes this extension brings are few, we found that them all very useful. If you're looking to add a little oomph to your current version of Firefox's Download Manager, we recommend you give this extension a shot.
A modification of the Firefox download manager that changes its appearance and allows it to be opened in a separate window, a new tab, or the sidebar.