my favorite way of downloading larger files / batch-downloading Rated 5 out of 5 stars
I like the fact that I can specify a default limit to the number of concurrent downloads, generally and per domain (website), and even the maximum number of downloading threads (segments) per file.
The auto-filenaming is very practical (but I wish the templates included the source web-page's title as a variable as well). Overwriting / auto-renaming of files is handled perfectly (intuitively and productively).
It resumes downloads if you interrupted them by exiting Firefox completely, the next time you start it.
DownThemAll does anything that you expect it to do and more, and it is one of the best pieces of download manager software that I've tried. I've been using it for a long time and it has made my life easier. If you're looking for a download manager add-on for Firefox, try this first, especially if you're more technically inclined (advanced computer user).