I'm still using the 2008 version of Microsoft Office for Mac OS, because I got it for free through my college's institutional license, and it still works under Mac OS 10.8 (Mountain Lion). I kept my eye on the Office 2011 Family Pack (1 user / 3 installs) because it was fairly cheap (~$120 at Amazon) and I have three machines to deal with (office, home desktop and home MacBook). I just found out that Microsoft has discontinued this pack in favor of their new cloud-based system, Office 365, which you have to subscribe to at $100 per year (but you can use it on five machines, whee!). Sure enough, Amazon itself doesn't sell the family pack any more, but some of its third-party sellers still have it at about $120. So I just ordered one, and am keeping my fingers crossed that Micro$oft will actually let me use it. Of course, I don't plan to upgrade again unless I absolutely have to.