Top 20 NuGet immutable Packages

MASBicudo Data Structures - Immutables, Continuous.
Json.Net serialization extension for Finalist
A base class for creating immutable composite user types
A base class for creating immutable user types
Code Fix for a record (immutable class/struct) constructor generated from get-only properties
A lightweight, flexible and easy to use do/undo/redo implementation based on immutable objects for .NET.
A member of the Visual Studio SDK
A member of the Visual Studio SDK
A member of the Visual Studio SDK
Inheritable tuples with protected members, correct equals contract and optional cacheable hashcodes.
Migrating from full framework to .netstandard
Provides fast and memory efficient alternatives to the collections in System.Collections.Immutable. Currently just includes SchematiqList as a replacement for ImmutableList.
Simple and small implementation of Immutable Collection.
Immutable collections that use trie as their internal data structure, and provide a direct replacement for the .net's implementation of ImmutableList and ImmutableDictionary
Package Description
Defines an IImmutableSet that implements IReadOnlySet.
Immutable versions of `Memory<T>` and `Span<T>`, because `ReadOnlyMemory/Span` doesn't imply the underlying memory won't be mutated. These types either wrap known immutable objects (`String`, `ImmutableArray<T>`), or they take sole ownership of a defensive copy of the underlying memory. They then pr...
Provides a read-only array type that is convertible from T[] and ImmutableArray<T>.
For C#/VB Universal Windows code (UWP), use UnitsNet instead. This is a Windows Runtime Component with reduced functionality to support all UWP languages, such as JavaScript and C++, and other runtime components.