Apple provides downloads for Intel's Indeo Video 3, 4, and 5 codecs for QuickTime in their Knowledge Base.
However, these codecs only work under OS 9, and therefore, only on PowerPC Macs. There are no OS X versions and none of Windows Media Player, Real Player, VLC, or MPlayer seem to be able to play these files.
The only workaround on PowerPC Macs (as described in the Knowledge Base Articles) is to launch the QuickTime Player under Classic. You'll then be able to play and export the movie, if QuickTime and the above-mentioned codecs are installed. On Intel Macs, of course, an installed Windows environment (via either Boot Camp or Parallels) can be used to play back these files.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20060928015506195