On the surface, El Capitan — coming this fall — doesn't appear to be an earth-shaking upgrade for OS X. There are some important underlying changes planned though, for instance impacting performance. Launching and switching apps will be faster, and for the first time Macs will have access to Metal, a previously iOS-only Apple graphics technology enabling more efficient rendering.
Featurewise, Spotlight will gain natural-language search requests, and the ability to pull up weather, sports, stocks, Web video, and transit info. Along those lines, Maps will offer public transit directions that can optionally be pushed to an iPhone.
A Windows 10-like Split View mode will make it easier to maximize two apps side-by-side, and Mission Control is being redesigned to be simpler. As a small touch, "shaking" El Capitan's mouse cursor will temporarily make it larger and easier to find.
Some other new features will include improved Mail, Notes, and Photos apps, and better support for Chinese and Japanese, for example through faster trackpad handwriting. People browsing the Web in Safari will finally be able to pin sites, push Web videos to an Apple TV, and selectively mute tabs without checking them one-by-one.