Today, I read a very interesting article from David Clunie on “open vs. closed standards in healthcare IT”. The short version is: HL7 is a closed standard, unlike the DICOM standard, which requires no fee for implementation and which, therefore, can be regarded as an open standard. Even the specification of the DICOM standard can be obtained free of charge.
Update (2013-02-21)
To be fair, I also have to reference the article “HL7 to Become a Truly Open Standard After All” from David Clunie. So, it seems that something is changing for good 🙂