smagi 

Typed, extensible lexing and parsing library in pure C#.

A basic reimplementation of Microsoft's code contracts for .NET.

Secure URL continuations for ASP.NET.

Partial application for System.Func and System.Action.

A lightweight CIL byecode processing library.

Extensions to LINQ 2 SQL and System.Data classes.

Efficient runtime reflection and structural induction.

Class library for declaring and manipulating tabular data using the EOT delimiter.

Class library for declaring and manipulating tabular data using custom delimiters.

A tiny, fast dependency injector that doesn't employ runtime code generation, making it suitable for use in restricted environments.

Combinators for composing expression trees.

A simple testing library to check that compilation fails on code fragments.

Extensions for web programming.

A set of interfaces ensuring correct implementations of the HTTP methods used by Razor Pages.

Forward mode and reverse mode dual/codual numbers for automatic differentiation.

Locale-specific functionality, like countries, states, postal addresses, phone numbers, etc.