EventFlow

EventFlow is an Async/await first CQRS and Event Sourcing DDD framework for .NET

FluentMediator

FluentMediator is an unobtrusive library that allows developers to build custom pipelines for Commands, Queries and Events

Xer.Cqrs

A simple library for creating applications based on the CQRS pattern with support for attribute routing and hosted handlers. Developed in C# targeting .NET Standard 1.0.

TinyMessenger

A lightweight event aggregator/messenger for loosely coupled communication.

Rx Event Aggregator

A portable event aggregator for pub-sub messaging, using Rx, for .NET 4+, SL5, WP8+ and Windows Store Apps

MediatR

Simple, unambitious mediator implementation in .NET

Mediator.Net

A simple mediator for .NET for sending command, publishing event and request response with pipelines supported