The Rubicon Rumble Pack for Quake has been released. It's a four map pack based off Rubicon 2 by Metslime/CZG. The mappack is getting rave reviews over at Func_Msgboard. I downloaded it and like it. It requires the QuakeSpasm engine R980, which you can get here.
It's available to download at Quaddicted and Dropbox. I took a couple screens of when I started playing, click “Read More” to play them. Be sure to read the readme, you need to set specific commandlines to run the mod. Enjoy!