Last year Apple gave its Mac operating system a visual overhaul, with OS X Yosemite. This year OS X's changes are a bit less obvious, but no less important, with a heavy focus on improving core performance.

After killing the cat theme two years ago, Apple is sticking with its California landmark theme, going with "OS X El Capitan." Apple's new OS is designed to improve experience and performance on the Mac, but it does have some new features as well.

The most obvious new way of working in El Capitan involves window management. El Capitan will add a new Split View, similar to Windows' "snap" feature. It lets you drag two apps next to each other, creating a combined full screen view.

Mission Control, Apple's spaces management feature, also now gives you more ways to arrange your windows – including creating a new full-screen space by dragging an app into the spaces bar. You can also create a new Split View space, by dragging another app into an existing full-screen space.

Mail and Safari don't get major overhauls this year, but there are a few new features – including swipe gestures (to keep or delete a message) and multiple tabs in the new mail composer window, as well as the ability to pin websites in Safari (just drag a browser tab to the left, where pins permanently reside). Safari also now has a feature (following in Chrome's footsteps) that lets you automatically find or mute a tab that has noisy auto-play audio running.

Spotlight and Finder get some updates as well, letting you more easily search for items using natural language. Apple's Craig Federighi demonstrated that he could type "documents I worked on last June" in Finder, or "mail I ignored from Phil" in the Mail app to immediately see the relevant results.

None of these are likely to be landmark features, so it sounds like (as rumored) Apple's developers put most of their time into improving performance and stability. Compared to Yosemite, Apple says that El Capitan has apps launching 1.4x faster, app switching up to twice as fast, display of first mail messages also happening twice as fast, and PDFs opening in Preview up to 4x faster.

Apple's Metal graphics technology, which showed up in iOS 8 last year, comes to the Mac in OS X El Capitan. Apple says Metal can give the Mac up to 50 percent faster rendering performance. That isn't likely to shift the heavily-tilted gaming balance away from Windows and in Apple's direction (the consumer Oculus Rift isn't even going to support the Mac at launch), but it shows that Apple is trying to make strides in that direction. And, if nothing else, it should improve overall performance for millions of Mac owners.

The first developer beta of El Capitan will be available today. Like with Yosemite last year, a public beta will arrive in July. Apple has already announced that OS X El Capitan will be a free upgrade, this (Northern hemisphere) Fall.

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