Hi ,
I was pretty disappointed about the windows-only turn that Quake Live took, so I was kind of happy finding a simple solution to play Quake Live on OSX. I'm using OSX Yosemite on a Retina 15 MacBook Pro. Here's a very simple tutorial:
1 - Install "Play On Mac": http://www.playonmac.com/fr/download.html
2 - Start "Play on Mac" App
3 - Start the installation script by clicking the "Try this patch" blue button in the very bottom of this page: http://www.playonmac.com/fr/app-2407-Quake_Live.html
4 - A dialog Window, asking you if you want to launch an external application, appears. Click "Launch Application"
5 - Follow the Basic Setup Dialogs
6 - You're going to choose which way to install Quake: Steam or Client. I recommend the latter one.
7 - When it's finished a shortcut with the right Icon is going to appear in your desktop.
8 - ENJOY !