This document describes the policy for end of (support) life for .NET packages in a stable supported distro, including LTS.
.NET is an open-source platform for building desktop, web, and mobile applications that can run natively on any operating system. The .NET ecosystem includes tools, libraries, and languages that support modern, scalable, and high-performance software development.
Cananoical collaborates with Microsoft to package .NET releases for the Ubuntu Platform: