In Pictures: OS X Mountain Lion arrives - the top 25 features

Move over for the new big cat

After five months of anticipation, OS X Mountain Lion is now available. The $20 OS upgrade for Intel-based Macs goes a long way to bringing iOS applications and capabilities into the Mac OS, and it adds a variety of new capabilities aimed specifically at computer users. Many changes are under the hood, such as enhanced security capabilities to protect the kernel during startup, and several add up to a better experience, such as scroll bars that widen automatically as you use them.