[from developer's site]
OpenQuicktime aims to be a portable library for handling Apple's
QuickTime (TM) popular media files on Unix-like environments. This
project was firstly designed to allow the porting of the 3ivx codec
on any Unix, but is now a completly separate and fully Open Source
project. Details:

o OpenQuicktime library contains no embedded codecs but has a plugin
  system to dynamically load audio and video codecs.
o OpenQuicktime contains no colorspace conversion algorithm.
o OpenQuicktime is fully portable and fully configurable with all
  the autoconfigure and automake magic we have been able to add.
o OpenQuicktime supports compressed headers (decoding only for the
  moment).
o OpenQuicktime supports Quicktime Sound System version 2.
o OpenQuicktime can support any inputs and outputs (file, HTTP,
  FTP, RTP, ...), in fact the functions used to read, write and
  seek are overloadable.
o OpenQuicktime has an overloadable plugin mechanism. This is a
  complexe feature which enables any application to use its own
  codecs instead of the OpenQuicktime ones.

WWW: http://openquicktime.sourceforge.net/