This is an official update for Quake 4. It will fully update any previous version of Quake 4 to version 1.4.2. It is recommended for all users.
This update affects pure server and protocol consistency, and adds a number of other multiplayer fixes including support for QUAKE 4 TV. This update will be necessary for Mac users attempting to play multiplayer against PC users with the PC 1.4.2 patch.