Ross Mason, a senior developer and member of the Mule project team told ComputerWire: Personally, I’d like to see us unite further and provide some examples shared over these offerings that demonstrate how well they interoperate. I think it’s important for open source projects in the integration space to at least play well together if not to actually form partnerships.

Mason said he has spoken with Iona about the Celtix project, and there are plans for interoperability between Mule and Celtix. There is already interoperability between Mule and ServiceMix, another open source ESB in its early stages that is also hosted by Codehaus, some of whose functionality is employed by Mule.

However, as for Sun’s open source ESB project expected this summer, Mason said: I would be happy to see Sun get their offering into this mix but I think they have a way to go in terms of technology, strategy and overall perception management of what they are trying to do. Sun could not be contacted by press time.

Sun said it hopes its ESB will become the first to support the Sun Java Business Integration, JBI, framework standard, which is spearheaded by Sun and the Java Community Process. JBI defines a standard container in which components from multiple vendors and various integration technologies can interact. Version 1.0 of Sun’s Java ESB is expected this summer.

Mason said Mule also hopes to support JBI. Mule has a JBI project underway that will reuse the existing Mule stack, namely the container, routing features and bindings (transport providers), this will be available for beta very soon, he said. Speaking with the various ESB vendors at JavaOne no one has actually got a solid JBI implementation yet so Mule will be entering the JBI with one of the most functional and stable implementations available.

I think it’s very exciting time for ESB vendors, he added. It seems everyone is grappling for a piece of the pie and open-source vendors should work together. After all, open-source is all about pushing the boundaries of software quality and I think this is more likely to happen if we coordinate our efforts. I don’t think any one ESB/JBI server will dominate, instead each will be used by different companies and departments, and the winners will be those that provide the most flexibility with other vendors.

Mason said Mule is working on expanding its ESB by supporting the WS-* web services standards stack, BPEL and JSR-94 (reusing existing components from Apache and Codehaus). And with our JBI interface, other JBI vendors will be able to take advantage of these features, he said.