This is Windows only. Is there a Mac OS version in the works? 

"Mac OS is not supported at this time due to the use of OpenGL 4.3 (for compute shaders), since Apple has deprecated OpenGL after version 4.1."

Looks like no unfortunately. 

Would it be possible to invert the order in the Mods' menu? First the installed mods and then those available for download. 

why do you guys have a mac or linux system if you want to game? 

 

While they suck at games, Macs are good at other things. 

How to get multiple user dirs working:

ironwail -basedir <full Q1 path> -basedir <mod dir>

Example:
ironwail -basedir c:\games\quake -basedir addons

Took me a while to figure that one out. 

With copper and using RAW 8-bit mode, the textures of health and ammo pickups warp as they approach the edge of the screen. I had this issue with 0.6.0 as well.

This doesn't happen with any other mod I,ve tried or with subtle and balanced mode.

does anyone know what causes this or how to fix it? 

This is more or less intentional. All mdls have texture warp in raw software emulation, as they did in the original game, and Copper replaces the bsp heath and ammo pickups with mdls so that they take their light value from the world, which they don't in vanilla. What you've encountered is the reason why id didn't make them mdls in the first place.

If you want to change this I believe you can put the original bsp pickups in a progs folder inside pak2.pak.

I wish there were separate options or at least cvars for each of the several things changed by 8-bit mode / r_softemu; that would be a better solution. 

https://github.com/andrei-drexler/ironwail/issues/74 

Yah. Separate cvars for the software emulation would be nice. Hopefully we'll get that in 0.8.0