Mule is an enterprise service bus (ESB) messaging framework. It is a scalable, highly distributable object broker that can seamlessly handle interactions with services and applications using disparate transport and messaging technologies
Mule is a messaging platform based on ideas from ESB ubuntures. the core of mule is a Seda-based service container that manages service objects, known as universal message objects or umos, which are plain old Java objects. all communication between umos and other applications is made through message endpoints. these endpoints provide a simple and consistent interface to vastly disparate technologies such as JMS, SMTP, JDBC, TCP, HTTP, XMPP, file, etc.
Mule applications usually consist of your mule instances ss the network. each instance is a light-weight container that hosts one or more UMO component. each UMO component will have one or more endpoints that it will send and receive events through.
The container provides a range of services for UMO components such as transaction management, transformation of events, routing, event correlation, logging, auditing and management. mule separates Object Construction from management meaning that popular IOC/di containers such as spring, picocontainer or Plexus can be used to construct your UMO components.
Home page is: http://mule.codehaus.org/