Top 20 NuGet http Packages

A module that compresses js into a single file, and css into a single file. More then likely you really want an msbuild task to do this. Get nuget package Talifun.Crusher.MsBuild if this is the case.
Specflow Generic Http Steps for testing APIs
A small, lightweight, embeddable HTTP / WebSocket server for .NET applications.
Spike-Engine is a software platform that facilitates building client-server applications for .NET people. In particular, it focuses on real-time and duplex communication, performance and productivity.
HttpResponseManager is a portable library. Using this library application can call and get Web API response using GET and PUT methods. User can also include the Headers while calling APIs.
A Machine.Fakes context configuration which fakes a standard http request
A fake implementation of HttpResponseBase
JSend.Client is a web client for performing basic CRUD operations on an API that conforms to the JSend specification.
The C++ REST SDK is a Microsoft project for cloud-based client-server communication in native code using a modern asynchronous C++ API design. This project aims to help C++ developers connect to and interact with services.
HTTP server mock is a really useful tool for testing, it will help you to mock HTTP requests.
HtmlAgality Adapter for iFish's Network Library (HTTP)
A tiny FSharp and CSharp Rest server