Top 20 NuGet env Packages

A .NET library to load environment variables from .env files
Injects values into config files directly or via environment variables. Can inject app settings, connection strings, or WCF client endpoints.
Simple and extensible way to make web.config/app.config/env vars/whatever easier to read and strongly typed!
Library for working with Environment Variables which helps with testing.
ASP.NET Core ServiceCollection extension for easy usage of env variables.
Env To Object (env-to-object) binding library for Bridge.NET projects.
Webpack Env (webpack-env) binding library for Bridge.NET projects.
Parcel Env (parcel-env) binding library for Bridge.NET projects.
Cloud Env (cloud-env) binding library for Bridge.NET projects.
Makes mapping key/value stores (appSettings, environment variables, NameValueCollections...) to POCs dead simple and highly extensible.
Support for Build Variables in Universal Apps
Fakta is a Consul HTTP API in F#
Makes mapping key/value stores (appSettings, environment variables, NameValueCollections...) to POCs dead simple and highly extensible.
Framework for compositing multiple application configurations together. Including environment variables, App.Config files and dev machine secrets.
A .NET library for parsing .env files and optionally injecting their variables into the environment
Allows you to list and manipulate open application windows.
Library for basic WAF features
Proteus.Utility.Configuration is a library that abstracts reading config values from e.g., app.config/web.config and supports their being overridden by ENVIRONMENT VARIABLES and/or a local.settings.json files.