The .Net Standard API compatibility contract

.NET Standard is a formal specification of .NET APIs that are available on all .NET implementations. It enables code sharing across different .NET platforms.

How It Works

Different .NET implementations (Framework, Core, Xamarin, Unity) implement specific .NET Standard versions. Code compiled against a .NET Standard version can run on any implementation that supports that version.

.NET Standard Versions

Version	Latest Supporting Implementation
1.0 - 1.6	.NET Framework 4.6+
2.0	.NET Framework 4.6.1+, .NET Core 2.0+
2.1	.NET Core 3.0+, .NET 5+ (not .NET Framework)

Note: Modern .NET (5+) no longer needs .NET Standard. Use net8.0 target framework directly.

// Example: Creating a .NET Standard library
// In .csproj file:
// <TargetFramework>netstandard2.0</TargetFramework>