Apple today has released the fourth developer preview of OS X 10.11 El Capitan. The operating system carries the build number 15A226f. Two weeks ago, the company pushed the third beta build to developers after initially introducing the operating system at WWDC last month. Beta 3 brought about a variety of minor changes, including changes to Mission Control, the Photos app, and the Calendar app.

In addition to allowing developers to test El Capitan, Apple is also offering public beta of the operating system and will also make it available to all retail employees to try.

As new features and changes are discovered in OS X El Capitan beta 4, we’ll update this post. Last month, we broke down some of the features in iOS 9 and OS X 10.11 El Capitan and noted some improvements Apple could make to the functionality of the features before launch later this year.

– You can no longer quickly swipe between desktops. You now have to fully stop at each Space.