The Odamex team has released an up-to-date package for Mac users. From their site:
After an eighteen month wait, Odamex has an official Mac OS X package once again! The package works on both x86 and PPC systems and has been confirmed to work with OS X 10.4 and higher.
This has been one of the most frequently received requests from our players. Many thanks go to Hyper_Eye who took the time to prepare and package Odamex for our loyal (and patient) Mac users.
The package is available for download on their homepage.