.NET Standard is a formal specification of .NET APIs that are intended to be available on all .NET runtimes. You can think of it as a simplified, yet expanded, Portable Class Library. It is a single library with a uniform API for all .NET platforms including .NET Core. You just create a single .NET Standard library and use it from any runtime that supports the .NET Standard platform.
You can now download Xamarin.iOS and Xamarin.Mac packages directly the Xamarin build bots. They are provided as-is and no QA or other validations were done on those builds (e.g. builds that failed internal tests are also published)
Xamarin has released a new set of preview builds with support for Xcode 8, iOS 10, watchOS3, tvOS 10, and MacOS Sierra. NOTE – These builds have been tested against Xcode beta 3 and beta 4.
Xamarin has released a third preview of the iOS Simulator for Xamarin.VS which provides you with a way to test and debug iOS apps on the simulator entirely from Visual Studio on Windows.
mkbundle tool in Mono has been updated, it no longer requires an installed compiler and can now cross-compile an . NET application into a native binary for a different architecture than you are currently running on. i.e. x86 can produce x64 binaries.