Last week I have been testing the glassfish openesb opensource soa platform and I am very surprised to see how far the opensource community is. Ok I think it is not so far as Oracle but give it some time and it will be a strong soa suite for free. The main difference is there is no mediator or esb part in openesb like Oracle has. The second difference Oracle has a esb and bpel console where you can see the soa processes. In the esb console you can change the esb processes at runtime. In openesb you have to do with the output console of glassfish server. There are also positive things about openesb. I like the xlst mapper it even knows anytype type and you don't have to add many copy entries in the bpel assign step ( you can do this in one xslt window). More important you have to configure the wsdl for the bpel and the adapters yourself. This is a great advantage for experience developers, you now know what it does because you have to configure it yourself. In Oracle Soa Suite you have a lot of wizards which helps you to create a esb or bpel process. You don't have to know how it works internally. This is fine untils you got a error or you have performance problems.
Here you see the components which you can use in the openesb BPEL designer
The BPEL process with on the left side the bpel web service with the request and response. On the right a partnerlink for the file adapter and the jdbc partnerlink ( database adapter in Oracle). Openesb provides a wizard which generates the wsdl for the jdbc adapter.
The xslt editor of the assign step.
Openesb gives you the option to create a composite project ( Oracle has this in Soa Suite 11g) where you can import the bpel projects as a jar. In the composite project you can use many adapters and deploy it as one project to the glassfish server
Here a example of a composite project where a bpel project is added as jbi module. I also connected an file adapter and activemq jms adapter to the bpel process.
Openesb has a great future and let's hope it will be a great or the best soa suite there is.