Handbrake?
Isn't that hardware 
Handbrake is described (by its author) as a "video transcoder" application but what it really is (and all it is) is a gui front end for a very well known command line application called ffmpeg. There are other free ones such as WinFF, Pazera, Avanti, FFmpeggui, ffmpeg-gui, Super, GVC, "Dotnet ffmpeg gui", (and plenty more - I gave up copying names from Google at this point) and some people even have the nerve to market paid-for ones without mentioning the actual free engine that does the work. You can write gui or CLI front ends for ffmpeg of varying complexity using batch scripts or programming languages. FFmpeg itself is very frequently updated, and one problem with these gui front ends on the Web, that may (or may not) matter, is that they tend to come packaged with whatever version of ffmpeg was used by the frontend writer at the time, and this can sometimes be woefully out of date and could have bugs or be sub-optimal in various ways. Occasionally you may find that the frontend writer has compiled ffmpeg themselves in some non standard way so you are locked into that version.
I haven't even mentioned Mencoder, a close sibling of ffmpeg.
