Top 20 NuGet configuration Packages

A minimal C# library for managing json config files in the .net framework
Autofac dependency resolver for the AccidentalFish.ApplicationSupport framework
Ninject dependency resolver
Console logger for the AccidentalFish.Application support framework
Dynamic Settings is a .NET library that allows you to load application settings from a variety of sources including environment variables, ConfigurationManager, text files, YAML files, and Redis.
A DynamicStore storage and configuration provider used for storing app data and configuration settings in local JSON files
A way to write more configuration with less typing
See the project page for more.
.NET CentralConfig client
Enables appsettings reload onchange also drop dependency on IOptions<T>
Write your .NET configuration files in C# and execute them using Roslyn.
A functional way of configuring functions
A .NET configuration library to simplify application configuration
A custom build target that automatically transforms config files for each environment defined
Dapplo.CaliburnMicro.Configuration is an extension to Dapplo.CaliburnMicro and brings Dapplo.Config.Ini configuration
Best.AvroEx.Serialize dynamic serialize lib for .NET Core and .NET 4.6+
Merlin manages configuration of software units of deployment.