MassTransit is
free software/
open-source .NET-based
Enterprise Service Bus (ESB) software that helps Microsoft developers route messages over
MSMQ,
RabbitMQ,
TIBCO and
ActiveMQ service busses, with native support for MSMQ and RabbitMQ. It supports multicast, versioning, encryption, sagas, retries, transactions, distributed systems and other features. It uses a "Control Bus" design to coordinate and the
Rete algorithm to route. Since it does not include "business monitoring" or a "business rules engine" (and requires programming to implement sagas for orchestration), MassTransit is typically considered to be in the category of "lightweight ESB" software.