Standards

Medical Software

OpenEHR / GEHR / CEN TC251 / ISO TC215: Common EHR Model based on Archetypes
Healthcare Domain Task Force (HDTF) / CORBAmed: CORBA IDL interfaces for multiple services
DICOM: Medical Imaging Specification
Health Level 7 (HL7): Reference Model and Messages for data exchange
Health IT Standards by the National Alliance for Health Information Technology

Software

World Wide Web Consortium (W3C): XHTML, XML, XSL etc.
Object Management Group (OMG): CORBA, UML

Others

Stichting Groupe RICHE
The Open Group
ISO/IEC JTC1
ASTM
NEMA
IEEE1073
X12
NCPDP