Apple - Subtitle editor for OSX?
Never tried this, but is is cross-platform: http://www.aegisub.org/
After i read your comments - IMHO you will need:
- Make .srt subtitles in any tools what you can manage to work (timing)
- Optionally repair .srt files in any texteditor - skip this if not needed
- Test the .srt subtitles with VLC or Quicktime/Perian
- If everything is OK - embed subtitles into video with http://code.google.com/p/subler/
An open-source, cross-platform solution is Jubler
I didn't try it, but it has a good amount of users on iusethis.
While I've never used this to create raw subtitles, here's the couple of programs I've tried for a similar purpose:
Subs Factory for creating the subtitles ($7.99). I've actually used it to editing subtitles, but well.
Subler for embedding them into the mp4. I've used this once or twice about a year ago, and it did what I needed. And it's always good to see such a nice project is still active!