elasticsearch 

Exposes all the api endpoints but leaves you in control of building the request and response bodies. Comes with built in cluster failover/connection pooling support.

Elasticsearch client, strongly typed interface to Elasticsearch. Fluent request builder, mapped responses and powerful query dsl. Uses and exposes Elasticsearch.Net

An IConnection implementation that utilizes Apache Thrift to talk with elasticsearch

This package is only useful if you use the low level client ONLY and do not use NEST but would like to use JSON.NET as your serializer

An IConnection implementation that uses System.Net.Http.HttpClient to talk with elasticsearch