Registered developers can find the OS update in the Developer Center. Updating from a previous OS X version requires downloading the OS X Software Update Seed Configuration Utility, then checking for the update in the Mac App Store’s Updates section. We’ll dig into the latest beta and report any notable differences between it and the OS X 10.11 GM.
OS X El Capitan 10.11.1 build 15B17c Seed Notes
The OS X El Capitan 10.11.1 update improves the stability, compatibility, and security of your Mac.
The official OS X 10.11 El Capitan version for everyone is set to be released later this month on September 30th.
Update: OS X 10.11.1 includes support for Unicode 8 and a range of new emoji like taco, burrito, cheese wedge, hot dog, middle finger, and unicorn head. The emoji are also included in iOS 9.1, which is currently in testing as well.