Top 20 NuGet mutable Packages

Class library for performing advanced operations with types, dynamic objects, expressions, and reflection.
Use this addin for F# to make setters for union types and eliminate need for CLIMutable attribute for records.
The mutable wrapper of Microsoft's .NET Compiler Platform ("Roslyn") syntax tree. For simple manipulation of C# files.
Visual Reactive is a Library for .NET platform (Currently Winforms), that is inspired by functional reactive programming React JS. Reactive programming is a paradigm that allows you to express the idea around a feature in one readable place, abstract mutable state away from your user interfaces and ...
Mutable tuple classes for those times when you need mutable, reference-type tuples
Transcend the limitations of strict instance immutability to increase performance. This framework will be expanded in the future, but presently only works with System.String.