[dfox]

MPEG 4 (taken as a the whole body of standards, not as two particular video codecs) actually has provisions for text content, vector video layers and even rudimentary 3D objects. On the other hand I'm almost sure that there are no practical implementations of any of that.

[duskwuff]

Oh, and that's only the beginning. The MPEG-4 standard also includes some pretty wacky kitchen-sink features like animated human faces and bodies (defined in MPEG-4 part 2 as "FBA objects"), and an XML format for representing musical notation (MPEG-4 part 23, SMR).

[giantrobot]

Don't forget Java bytecode tracks!