IFC - Industry Foundation Classes
The Industry Foundation Classes IFC specification is a neutral data format to describe, exchange and share information typically used within the building and facility management industry sector. IFC is the international standard for openBIM and with IFC4 an ISO standard (ISO 16739).
The IFC specification is developed and maintained by buildingSMART International, bSI. The official website to publish IFC and related specifications is buildingsmart-tech.org. buildingSMART International also organizes the official IFC certification program, see buildingsmart-tech.org/certification.
The IfcWiki is an open portal to publish and share information about IFC, it is not an official site of buildingSMART International. However the bSI acknowledges the importance of an open knowledge base around its products, such as IFC, and supports this initiative.
IFC for Buildings - IFC for Bridges (IfcBridge) - IFC for Roads (IfcRoad)