Loki Software published a big metal box for the Linux version of Quake III Arena. id Software did the port themselves & compiled Linux binaries on-part with other platforms each time they released a “point release”. The last proprietary version is 1.32c.
id Software released the complete source code for Quake III Arena under the GNU General Public License v2 on August 19 2005. That allowed the emergence of the ioquake3 community that continues to support & develop the game engine.
Loki original binaries are completely unnecessary, you can simply install the game with your package manager:
apt-get install quake3