Top 20 NuGet AJAX Packages

A superset of the popular JSON format. Json+ is designed for ease of editing and is capable of variable substitution.
The logic which can be utilised to build a Compser app/extension
Fast validation around Newtonsoft.Json.Schema. Provides a generator of Linq Expression trees around JSchema instances. These expression trees can be compiled for validation speeds that far exceed Newtonsoft's implementation.
Formatting and naming convention rules for Firestorm.Endpoints.
Masks values of specified properties in a JContainer.
Core utility to access and manage HoxWi Platform.
Provides an abstract "JSON TextWriter Trace Listener" implementation which emits trace events formatted using JSON.
Newtonsoft.Json serializer for STRHM ( Strongly typed implementation for Redis StackExchange client, when using hashset functionality ).
JRequest.NET is a powerful library which allows applications to call web APIs using JSON.
JSON serialization capabilites for Tiger Types.
Various utilities for working with JSON schema. Contains a very fast validator.
(fork of project by Kris Craig) Reddit.NET is a .NET Standard library that provides easy access to the Reddit API with virtually no boilerplate code required.
JSON support for Dommel.
Authentication and service implementation for the YouTube API.
Authentication and service implementation for the Google Analytics APIs.
Open source .NET library for parsing and serializing RSS, Atom, and JSON feeds.
Adds support to Newtonsoft.Json for mapping properties using JSONPath expresions.
WebApiRunner is an aspnet core application framework to host simple rest services with minimal plumbing required.