I have an amazing tool called 7edit for editing and sending HL7 v2 messages. I've searched hours for a similar tool for HL7v3 without luck. They're all web based, crappy, broken links, etc.
InterSystems HealthShare is a healthcare informatics platform for hospitals, integrated delivery networks (IDNs) and regional and national health information exchanges (HIE). HealthShare includes health information exchange, data aggregation, workflow, text analysis, and analytics technology.