Xcode 8.1 Release was released on 27 Oct 2016 and requires macOS 10.11.5+.
It can be downloaded from https://download.developer.apple.com/Developer_Tools/Xcode_8.1/Xcode_8.1.xip.
Release notes are located at https://developer.apple.com/library/content/releasenotes/DeveloperTools/RN-Xcode/Chapters/Introduction.html#//apple_ref/doc/uid/TP40001051-CH1-SW24.
The SDKs it contains are:
- iOS 14B72
- macOS 16B2649
- tvOS 14T328
- watchOS 14S471a
The compilers it contains are:
- clang 8.0.0 (Build 800.0.42.1)
- swift 3.0.1 (Build 800.0.58.6)
- LLVM-GCC 3.9.0 (Build )