iOS 9.3.5 provides an important security update for your iPhone or iPad and is recommended for all users.
WWDC 2016 Keynote.
At 10 A.M PDT you could watch the WWDC2016 Keynote.
About the security content of Xcode 7.3.1.
The future would be macOS during the next WWDC ?
Mac OS 9 > Mac OS X > OS X > macOS ?
WiFiKeychainProxy(8) / BSD System Manager’s Manual / WiFiKeychainProxy(8)