We have explicitly attempted to leverage the hard work done by folks on other fantastic open source projects. In particular, the HAPI project for HL7 to XML, the MULE project for the underlying message bus framework as well as Jetty for the embedded webserver/jsp component of Mirth. We also use Apache Rhino to support the filtering and transformer javascript and HSQLDB for a lightweight embeddedable RDB. I don't think this project would be possible without all those components.

I think by leveraging these other projects and building 'meta-tools', the open source community can take on work that would be a difficult challenge otherwise. In particular, the healthcare industry, having so many legacy applications that will still be around for a while, can benefit from this sort of tool.