.NET (previously named .NET Core) is a free and open-source, managed computer software framework for Windows, Linux, and macOS operating systems. It is a cross-platform successor to .NET Framework. The project is primarily developed by Microsoft employees by way of the .NET Foundation, and released under the MIT License.
In November 2020, Microsoft released .NET 5.0 which replaced .NET Framework. The "Core" branding was removed and version 4.0 was skipped to avoid conflation with .NET Framework. It addresses the patent concerns related to the .NET Framework
.NET 6, .NET 7 and .NET 8 are projected on Nov'21, Nov'22 and Nov'23