I'm not a programmer but my understanding is that HL7 refers to a 7th level of ISO standards that cover all aspects of interoperability including clinical, financial, and administrative functions. It is an international standard. I am now looking at various electronic health record software programs and would like to use ACT as the front end. I spoke with a number of different vendors, and they are comfortable using any of the new Medical Practice Management programs as the front end because the newer programs (developed or updated over the past few years) conform to HL7 standards. That way, it is very easy (so they say) to write an interface (like th ACT LINK to Quickbooks) to basic demographic data and to custom fields. Interoperability of databases SHOULD be easy, but seems like every manufacturer wants to protect their base by locking in their users. I remember years ago that there was a standard, I think called OLDB, which was supposed to solve this problem.