Note:
The web site still list it like updated on 2004-11-01. But the readme says updated on January 27, 2006. And the UDF.IFS file was updated on 2006-01-30.
You need paid Passport Advantage access to download this file. Once you log in you can see that the file was posted on 2/14/2006.
Source: OS/2 Warp News and Rumors