Top 20 NuGet configuration Packages

Configgy extensions to incorporate Microsoft.Extensions.Configuration configuration mechanisms
Helper for adding configuration sources in the following order: JSON files from config directory, JSON files from command line, environment variables, command line arguments.
Configuration.EntityFramework is a custom configuration provider for the .NET Core Configuration system. It's built on EntityFrameworkCore allowing configuration settings to be stored in a wide variety of repositories
GoFigure provides unified .NET, Silverlight, jQuery, and Windows Phone configuration, providing the flexibility to quickly swap configuration sources from local file-based settings to anywhere you desire (e.g. remote SQL Server storage, WCF XML service, RESTful JSON service, custom, etc.).
Contains a base class for UnitTests that supports testing code that uses the dependency injection pattern.
Formo.Cloud works like Formo, but for applications using Azure Configuration.
Unify is an automatic configurator IoC container via annotations. It is based on the principle of separation of layers and can detect injections forbidden dependencies.
Extensions for WCF: configuration, behaviors and Inversion of Control.
Generates custom instrumentation configuration files for New Relic - see the project page for more information. Mark up your assemblies, classes and methods to get fine-grained control using the [Instrument] attribute.
Web and HTTP classes and extensions.
Simple & performant model mapping
Common functionality for ASP.Net MVC applications - configuration, generic controller, generic repository, generic version history controller, access denied attribute, account management.
.NET API for KonfDB - A configuration service for multi-tenant cross-platform applications
A helpful library for configuring and managing NHibernate session factories and sessions
A very simple library to provide typed access to configuration files in JSON format.
Strongly typed config for Azure Cloud Services. Code generation of Settings: cscfg and csdef and reader
Configures AppBoot core to use Unity Container
Configures AppBoot core to be used in an Web Api app
Core interfaces and components for the Accidental Fish Application framework
Allows to maintain several connections to epifind within a single config.