Xcode 11.3 GM was released on 10 Dec 2019 and requires macOS 10.14.4+.
It can be downloaded from https://download.developer.apple.com/Developer_Tools/Xcode_11.3/Xcode_11.3.xip.
Release notes are located at https://developer.apple.com/documentation/xcode_release_notes/xcode_11_3_release_notes.
The SDKs it contains are:
- iOS 13.2.2 (Build 17B102)
- macOS 10.15.1 (Build 19B90)
- tvOS 13.2 (Build 17K90)
- watchOS 6.1 (Build 17S80)
The compilers it contains are:
- clang 11.0.0 (Build 1100.0.33.16)
- swift 5.1.3 (Build 1100.0.282.1)