This binaries where compiled ussing Icculus Quake II source code r0.15.
They are fully compatible with all Quake II v3.20 for Windows, Quake II v.3.21 for Windows, Quake II v3.21 for Windows, and Quake II v3.21 (With Q2Max) for Linux.
The Icculus r0.15 is mainly a tweaked version of ID Software source code v3.21, the main diference is that Icculus version really work with no bugs detected.
This binaries are the legacy ones, with no fancy graphics...