Mac OS X MountainLion
Mac OS X Mountain Lion (10.8.x), released on 25 July 2012, is the currently supported operating system for Macs on the Middlebury campus.
Update (March 5, 2015): 10.8 and 10.9 (Mavericks) are the recommended Macintosh operating systems. OS 10.10 (Yosemite) is required on the newest computers, but as of version 10.10.2 is still not recommended. See http://go.middlebury.edu/yosemite for detailed information.