Mac OS X 10.10 Yosemite

Apple hasn't even put it in the app store yet despite having a link to it on their website.

I've been on the beta for Yosemite for a few months, no issues so far for me.

EDIT: Whenever I start a match, the bottom of my screen bumps the mouse back up a few inches instead of scrolling, but toggling vsync in the video options fixes it every time. Didn't think of that since I've just gotten used to toggling it lol.

I have upgraded to Yosemite and the only issue I have seen is an inability to perform any other ping than a request for assistance. Other than that it appears to work fine.

my mouse keeps getting locked to the top of the game in play - MacBook Pro Retina...

The "pinging" control when you right click doesn't work in Yosemite. The mouse reads as all the way up and you can only click on "Danger". Really frustrating.

it works, but few bugs are there http://boards.na.leagueoflegends.com/en/c/bug-report/dhxqz6uw-mac-os-x-1010-yosemite-software-mouse-bug-on-retina-display-macs