Yes, I have been playing around with Mule. No, it's not the P2P client. That's emule!

"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." - from Mule's website

Mule caught my attention because the architecture quite impressive. I do have some experience about what it aims to solve in the enterprise environment. Documentation is quite good and easy to understand. I am tinkering the Hello World sample and it's pretty easy to use. I haven't been able to run my own customized application though but we will get there.

Check out the Mule's kick-ass architecture here…

http://mule.mulesource.org/wiki/display/MULE/Architecture+Guide

Here's a snapshot of the kick-ass implementation. It would make other ESB frameworks run for its money. haha