Mule is based on ideas from Enterprise Service Bus (ESB) architectures. The key advantage of an ESB is that it allows different applications to communicate with each other by acting as a transit system for carrying data between applications within your intranet or across the Internet. There are currently several commercial ESB implementations on the market. However, many of these provide limited functionality or are built on top of an existing application server or messaging server, locking you into that specific vendor. Mule is vendor-neutral, so different vendor implementations can plug in to it. You are never locked in to a specific vendor when you use Mule.  

Mule provides many advantages over competitors, including:

• Mule components can be any type you want. You can easily integrate anything from a "plain old Java object" (POJO) to a component from another framework.
• Mule and the ESB model enable significant component reuse. Unlike other frameworks, Mule allows you to use your existing components without any changes. Components do not require any Mule-specific code to run in Mule, and there is no programmatic API required. The business logic is kept completely separate from the messaging logic.
• Messages can be in any format from SOAP to binary image files. Mule does not force any design constraints on the architect, such as XML messaging or WSDL service contracts.
• You can deploy Mule in a variety of topologies, not just ESB. Because it is lightweight and embeddable, Mule can dramatically decrease time to market and increases productivity for projects to provide secure, scalable applications that are adaptive to change and can scale up or down as needed.

MuleSource also provides administration tools that allow you to manage your deployments (Mule HQ) and control your infrastructure (Mule Galaxy). These tools are described in more detail in the Administering Mule section.