In Pictures: OS X Mountain Lion arrives - the top ...
A more professional calendar
Let's face it: iCal was never as sophisticated as the calendars in Outlook or Lotus Notes. OS X Mountain Lion's version of iCal -- renamed Calendar -- adds a calendar widget to make it easier to pick dates for your appointments, and its repeating-event capabilities now include options like the third Wednesday of the month. Parity at last!
In Pictures: OS X Mountain Lion arrives - the top 25 features