mono-4.0-gac 4.2.1.102+dfsg2-4ubuntu2 (amd64 binary) in ubuntu xenial

 Mono is a platform for running and developing applications based on the
 ECMA/ISO Standards. Mono is an open source effort led by Xamarin.
 Mono provides a complete CLR (Common Language Runtime) including compiler and
 runtime, which can produce and execute CIL (Common Intermediate Language)
 bytecode (aka assemblies), and a class library.
 .
 This package includes a version of the GAC (Global Assembly Cache) tool
 (gacutil) used by Mono to store shared CIL (Common Intermediate Language)
 libraries, for CLI 4.0