Does this skill add runtime overhead to my application?

No, the recommended tools (PolySharp and Polyfill) are source generators that work at compile-time, adding zero additional runtime dependencies.

Can I use modern C# features like 'required' on older .NET versions?

Yes, this skill provides guidance on using PolySharp to enable modern syntax features on older frameworks like .NET Standard 2.0 or .NET 6/7.

What is a polyfill-first approach in .NET?

It is a strategy that prioritizes using compiler-synthesized stubs (PolySharp) or BCL backports (Polyfill) over conditional compilation (#if) to keep the codebase clean and maintainable.

When should I use conditional compilation instead of a polyfill?

Use #if blocks for runtime behavior differences, performance-critical optimized paths, or platform-specific APIs (like Windows Registry) that cannot be polyfilled.

.NET Multi-Targeting Strategy

Name: .NET Multi-Targeting Strategy
Author: rudironsoni

byrudironsoni

0•

Developer Tools

Streamlines .NET multi-targeting by implementing polyfill-first strategies and conditional compilation for cross-version compatibility.

This skill provides comprehensive guidance for developers building .NET libraries or applications that must support multiple Target Frameworks (TFMs). It emphasizes a 'polyfill-first' approach using PolySharp and SimonCropp/Polyfill to minimize brittle conditional compilation blocks. By guiding the decision-making process between compiler-synthesized polyfills, BCL API backporting, and TFM-specific source files, it ensures codebase maintainability while enabling modern C# features on legacy runtimes. It is an essential tool for library authors looking to maximize reach without sacrificing developer experience.

Key Features

01BCL API backporting strategies using SimonCropp/Polyfill

02PolySharp integration for modern C# syntax on older TFMs

03Standardized patterns for TFM-based preprocessor symbols

04API compatibility validation using EnablePackageValidation tools

05Decision matrix for polyfill vs. conditional compilation selection

060 GitHub stars

Use Cases

01Supporting legacy .NET Standard 2.0 while utilizing modern C# 12+ language features

02Maintaining high-performance code paths for modern .NET versions with stable fallbacks

03Developing cross-platform .NET libraries that require TFM-specific runtime optimizations

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add rudironsoni/rulesync-dotnet dotnet-multi-targeting

For use in Claude.ai and ChatGPT

Key Features

01BCL API backporting strategies using SimonCropp/Polyfill

02PolySharp integration for modern C# syntax on older TFMs

03Standardized patterns for TFM-based preprocessor symbols

04API compatibility validation using EnablePackageValidation tools

05Decision matrix for polyfill vs. conditional compilation selection

060 GitHub stars

Use Cases

01Supporting legacy .NET Standard 2.0 while utilizing modern C# 12+ language features

02Maintaining high-performance code paths for modern .NET versions with stable fallbacks

03Developing cross-platform .NET libraries that require TFM-specific runtime optimizations

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add rudironsoni/rulesync-dotnet dotnet-multi-targeting

For use in Claude.ai and ChatGPT