Piggybacking off of the operating system before it - OS X Yosemite - El Capitan claims to be faster and come with some nifty new features for desktop Mac users.
But one question remains: Why in the world did Apple decide to call it El Capitan?
The history of OS X naming goes all the way back to 2001. The first official version of OS X was dubbed "Cheetah." Then, until 2012, each following operating system was named after another fast and agile cat. The last feline-named version of Apple's Mac operating system was Mountain Lion.
Then in 2013, Apple made a change. OS X 10.9, instead of representing yet another cat-like species, was instead dubbed Mavericks. At its unveiling, Craig Federighi told the audience the operating systems to come would be named after well-known California locations. Of course, Mavericks is a favorite surfing spot in Northern California.
Federighi joked, "We don't want to be the first development team to be delayed by the lack of big cats."
Following Mavericks was OS X Yosemite, which was named after Yosemite National Park.
And now we have El Capitan, which (despite sounding a bit like a Mexican restaurant) is actually a vertical rock formation located within Yosemite National Park.
Apple didn't provide a formal reason for why it chose El Capitan, but the rock formation is considered an important California landmark. Hikers know it well, and it's even considered one of the best places in the world for rock climbing and base jumping.
Like Mavericks, it's a destination for agile and daredevil-ing sport enthusiasts.
So while there's no way to know for sure what Apple will choose for its next OS X name, chances are it will likely focus on yet another geographical landmark in California.
You can see a full breakdown of all the new features coming to your Mac with OS X El Capitan by clicking here.