Apple says that Mountain Lion has over 200 new features, but truth be told, it’s hard to tell where the 200 features are unless you looked hard. One of the most noticeable new features, however, has got to be the new Notification Center, among a handful of other core highlights which we'll touch upon briefly.
As the name suggests, Notification Center combines elements of Growl and Notification Center from iOS devices. Alerts from applications appears as pop-ups and if you have a trackpad, a two finger swipe from right to left reveals a vertical list of notifications from various applications. You can also click on the Notification Center icon on the top right-hand corner to invoke this vertical list of notifications. At this point of time, only a handful of applications support Notification Center but we are sure that more will in the near future as they are being updated for Mountain Lion.
Another new feature of Mountain Lion that you are likely to come across is Gatekeeper - a security feature that prevents users from opening potentially dangerous apps. By default, Gatekeeper will only allow your Mac to run apps downloaded from the Mac App Store and by identified developers. To run other third-party apps, you’ll need to delve into the Security and Privacy tab in your System Preferences and tweak the settings to run unsigned apps. With Gatekeeper, Apple is hoping to make Mountain Lion its most secure OS yet, at least for not so tech-savvy users. This all sounds very much like the Windows User Access Control (UAC), only smarter and less annoying.
With Mountain Lion, Apple has also ditched iChat in favor of a new Messages app. The new Messages app resembles Messages on the iPad and it also supports Apple’s iMessage instant message protocol. In theory, it’s supposed to let users take their conversations from their desktops to their iOS, but in practice, it’s pretty haphazard as messages get delivered to both your devices. Furthermore, the iMessage service, despite having been rolled out since October last year, is still a bit wonky at times as messages sometimes get missing or get delivered in a bunch. Clearly, this feature needs further refinement.
Apple has also introduced the latest version of Safari with Mountain Lion. Aesthetically, you’ll notice that Safari 6 loses its search bar and instead has a unified search and address bar, not unlike Chrome. Safari 6 also introduces iCloud Tabs which syncs open tabs across your Mac and iOS devices. iCloud Tabs works for Mountain Lion but mobile devices will have to wait until the release of iOS 6.
iCal has now been renamed to Calendar. The pointless page curling animation has been ditched and the list of calendars, which was displayed as a pop-over in Lion, has been reverted to a proper sidebar.
Reminders and Notes from iOS devices now have dedicated equivalent apps on OS X. If you’ve setup iCloud on your Mac, reminders and notes will all sync automatically, so any reminder or note that you create on your Mac will automatically appear on your iOS and vice versa.