In January of 1997, Health Level Seven (HL7) began developing Version 3.0 of its standard. The Version 3 effort represents a transformation of the way that HL7 and its Technical Committees will develop future HL7 information interchange standards. This transformation involves applying object-oriented modelling to the development and specification of information interchange standards. This paper discusses the rationale that led HL7 to undertake this change and provides an overview of the Version 3 Message Development Framework which is HL7's new methodology. It also considers the features of the Version 3 methodology that can facilitate the development of international collaboration and consensus in health informatics standards.