I've downloaded the codecs file from mplayerhq.hu, renamed it and linked as suggested by Jason Perlow in Linux Magazine, and http://stanton-finley.net/fedora_core_3_installation_notes.html.
The players can handle .avi, qt and .mov files just fine. Some of them will even play the sound track of the wmv files.
Is there another source for these codecs?
-- A. Rick Anderson