Top 20 NuGet messenger Packages

FatQueue.Messenger.Web
FatQueue
C# library for FB Messenger API
Event aggregation (Pub-Sub) library for Xamarin and .NET applications. This is basically the MvvmCross Messenger plugin without the MvvmCross part
Unofficial Facebook Messenger Platform follow https://developers.facebook.com/docs/messenger-platform
Bindings of the Facebook Messenger Send API classes for .NET to building bots
Simple TCP and UDP messaging framework. The TCP Messaging functionality uses a two-way connection.
A messenger for Bridge
A simplified version of MVVM Light Messenger only.
Facebook Messenger Connector: F# library for messenger API
Facebook Send API Wrapper for .NET