OS X 10.11: El Capitan (Gala)

OS X El Capitan (version 10.11) is the twelfth major release of OS X (renamed to macOS in 2016), Apple Inc.'s desktop and server operating system for Macintosh. It focuses mainly on performance, stability and security. Following the Northern California landmark-based naming scheme introduced with OS X Mavericks, El Capitan was named after a rock formation in Yosemite National Park, signifying its goal to be a refined version of Yosemite. El Capitan is the final version to be released under the name OS X. El Capitan received far superior reviews when compared to Yosemite.

The first beta of OS X El Capitan was released to developers shortly following the WWDC keynote on June 8, 2015.The first public beta was made available on July 9, 2015. There were multiple betas released after the keynote. OS X El Capitan was released to end users on September 30, 2015, as a free upgrade through the Mac App Store