Doesn't Work Anymore w/Alternatives Rated 1 out of 5 stars

I also found this one, https://addons.mozilla.org/en-US/firefox/addon/opendownload-271182/

I was able to find a link on google for the old link to the rundownload-1.2 which was an Experimental Add On that Firefox has since removed from the search results, https://addons.mozilla.org/en-US/firefox/addon/rundownload/.

In the event the above link dies.
I also uploaded the Xpi file to hotfile for anyone who's interested in using it.
http://hotfile.com/dl/98077416/ee19f5b/rundownload-1.2-fx.xpi.html
Just save the file & tell windows to open with Firefox to install.

This user has a previous review of this add-on.