Middleware has been a passion of mine as long as I have been involved in IT. I even once wrote my own Object Request Broker back in the early 90's. It's always hard for people to completely understand middleware because it's the software "glue" or "plumbing" that holds everything together. Like the plumbing pipes, it's not something you see every day, but you know how important it is if it's not working 
So much of the technology and methodology in IT (as in many things in life) run in cycles. Distributed computing, remote procedure calls, virtualization, and cloud computing have been around since the 70's. IT tends to run in cycles of centralized and decentralized processing depending on network bandwidth and interface demands.
Service Oriented Architecture (SOA) and Enterprise Service Buses (ESB) are both examples of another evolution of the cycles that occur around distributed computing and composite applications. Many IT organizations are in the process of deploying or planning SOA environments.
Any distributed computing environment has many advantages as well as many challenges that need to be addressed. To help organizations deal with end-to-end SOA deployments, we have created a complete Open Source SOA solution. This solution focuses on using SOA to address many of the business problems CIOs in large organizations are dealing with. It focuses not on the SOA technology, but instead on how SOA can increase the flexibility of legacy applications, reduce overall cost, provide composite information to end users faster, reduce deployment times, and aid in application consolidation, while still avoiding expensive proprietary lock in (it's all open source).
You can also see that Gartner provides very positive ratings on this open source SOA middleware suite.
Recently, Ashesh Badani and I got together and recorded a 
that goes over in detail the evolution of distributed computing to the current state of SOA (it's always important to know the background), as well as how SOA is being used in the Federal Government, and some of the technical and business challenges involved. If you are looking at SOA or in the process of deploying a SOA environment, please take the time to listen in.
