Apple's new Macintosh operating system, OS X 10.11 "El Capitan," is named after a prominent rock formation in Yosemite National Park. That's fitting because the new OS is designed with rock-solid stability in mind. El Capitan is the 12th iteration of the OS powering Apple’s desktop computer lineup, and as the name implies, it stands on the shoulders of its predecessor.
Just as iOS 9 was built on the foundation laid by iOS 8 for mobile devices, El Capitan improves on the many changes introduced in 2014's Yosemite -- which included new features such as Continuity and a smarter Spotlight search tool. El Capitan adds more polish than features, though there are quite a few of those to explore, as well.
Among the changes made to apps and sprinkled throughout the operating system are better security and a move to Apple's Metal graphics technology (which debuted in iOS) for the system and apps. (Metal replaces OpenGL.) El Capitan also cements in place the adoption of Apple's home-grown programming language, Swift, which allows developers to write apps with smaller latency and more efficient performance.
Like other recent OS X releases, El Capitan is a free download from the App Store. The system requirements are 2GB of RAM and 8GB of available storage. El Capitan will run on Macs that date as far back as mid-2007. (If you're still using a Mac from 2007, though, you should really look into upgrading your hard drive to an SSD for more 2015-like performance.)
But while older Macs can run El Capitan, those systems can't take advantage of all of its features. For instance, although El Capitan is designed to take advantage of both the CPU and the GPU for processing power, only Macs with modern graphics cards -- basically, those released since 2012 -- will be able to utilize this feature. (More on this below.)
Metal and Swift
The addition of Apple's Metal graphics technology is good news for gamers and other users. Metal is a set of application program interfaces (APIs) designed to supplant OpenGL. The Metal API is actually an Apple-designed combination of OpenGL and OpenCL, which debuted last year in iOS 8. (OpenCL is used to take advantage of every processor on a computer, CPU and graphics card included.)
Metal was designed for efficiency -- a requirement for mobile devices that need long battery life -- and is a much lighter API for graphics compared to OpenGL, letting the graphics card be used more effectively and freeing up the CPU for other tasks. For desktops and laptops, Apple rewrote OS X system software (like the Graphics stack) to take advantage of Metal, resulting in a 50% improvement in rendering performance system-wide and 40% better efficiency (the latter will help laptop users by prolonging battery-charge life).
Apple boasts that El Capitan is 1.4 times faster than previous OS X versions for app launching, twice as fast at switching apps and four times faster at opening PDFs. At the same time, Apple claims a 70% reduction in CPU usage compared to apps written using OpenGL.
Adobe representatives on stage during Apple's September 9th event claimed an eight-fold improvement in using the Adobe After Effects graphics software. Users should find that their systems are more responsive with smoother animations and faster application launches. There is also the promise of future improvements for games and other apps; however, those games and apps must first be rewritten to take advantage of Metal.
Another under-the-hood technology available to developers is Swift 2.0, which is designed to simplify coding (relatively speaking) while making it easy for OS X software to take advantage of the built-in hardware -- such as using the graphics card for data processing when possible. I'm not a programmer, but anything that allows developers to streamline their software is a good thing.
Changes you can see
Not everything in El Capitan is behind the scenes and waiting for developers. There are some user-facing features as well.
The first thing astute users may notice is that El Capitan uses a new system font: San Francisco. This font is designed to make text more legible for Apple's high-definition Retina displays. It works as intended, but the difference will probably be overlooked by any but the most fastidious font fanatics.
The updated Finder builds on Yosemite's improvements by applying a new split-screen app mode in addition to the full-screen mode that debuted in Yosemite. The split-screen mode can be enabled in a couple of ways. First, you can drag a Finder window to the top of the menu bar and then drop that window on an existing full-screen app space in Mission Control. Or you can press and hold the green button on an app window -- doing so will make that app fill up half the screen and any open windows display in miniature, letting you select one to fill the other side of the screen.
A clear divider separates the two apps, and each operates independently. The divider can be dragged from side to side to adjust each app's window size. The menu bar at the top of the display automatically changes to accommodate the front-most app, which is normal app behavior Mac users are accustomed to.
Managing windows via Mission Control also received attention in El Capitan. Any window dragged to the title bar will activate Mission Control, which lets you move apps to different virtual desktops. Dragging an app window into any existing Space automatically places the window there; dragging the window into a Dpace occupied by a full screen app activates a split-screen view; and dragging a window to the upper right of the display creates a new Space with that window in it.
Spotlight, now with more Siri
Spotlight receives some really useful upgrades in El Capitan. Yes, you can move around the search field and results window; they're no longer locked in place at the center of your display. There's also added functionality in search results: Spotlight can check sports data (such as information about favorite athletes or scores, team schedules and standings); it can check weather conditions and forecasts; and when you search for a company's ticker symbol, it can look up stock prices.
The biggest improvement comes in the form of queries, similar to the ones you can ask Siri on iOS. Spotlight now supports natural language search, which generally means Spotlight is as useful as Siri, even though the searches have to be manually typed rather than spoken aloud as you would with an iPhone.
At the iPhone 6S launch event, Craig Federighi, Apple's senior vice president of software engineering, demonstrated this function by typing a search for emails from Phil Schiller that had been ignored. The search results showed unread messages from Schiller. I've used Spotlight to search for documents and videos created during certain time periods, as well as to search for New England Patriot game scores and standings.