SlimMessageBus

Lightweight message bus with transports for popular messaging systems (Kafka, Redis, Azure Service Bus, and others) and in-memory communication.

Silverback

A simple but feature-rich message bus for .NET core (supports Kafka, RabbitMQ and MQTT).

Brighter

Command Dispatcher, Processor, and Distributed Task Queue https://www.goparamore.io/

Foundatio

A common interface with in-memory, Redis and Azure implementations.

RabbitMQ.NET

Implementation of an AMQP client library for C#, and a binding exposing AMQP services via WCF

Hangfire

Incredibly easy way to perform fire-and-forget, delayed and recurring tasks inside ASP.NET applications

Gofer.NET

Easy C# API for Distributed Background Tasks/Jobs for .NET Core. Inspired by celery for python.