Apple made the Mac OS X 10.11 El Capitann beta 4 available to developers today. Featuring experience and performance gains, El Capitan is an incremental update to Yosemite, which was a major overhaul of various OS X features, user interface elements and functionality. Other features include Split View, improved Mission Control and a more intuitive Spotlight search among others. El Capitan lands this Fall as a free upgrade to existing Mac users.