Txt2VobSub generates vobsubs[idx/sub] subtitles from srt or txt subtitles . The quality of the subtitles is superb . You can select custom colors and position of your subtitles.
It can be used in order to watch on your standalone divx player subtitled movies. Your divx player must be vobsub [idx/sub] compatible.

VobSubMuxer can join more than one languages on one single vobsub file (idx/sub). Vobsub files, generated by the extracion of the dvd, can contain more than one language streams.
So if you rip an dvd on your computer, the extracted idx/sub package may contain more than one languages in one file[sub/idx].This is an really good solution if you want to watch your film (test.avi) with all the supported languages that where on dvd (test.sub/test.idx)