• IFC2x3-TC1 - IFC2x Edition 3 Technical Corrigendum 1 - documentation and constraint only corrigendum to update of IFC2x3, published in July 2007
• the IFC2x3 release and IFC2x3-TC1 update are equal in terms of the IFC exchange file and both are used for IFC2x3 implementation and certification
• the IFC2x3 release and IFC2x3-TC1 are now strongly recommended for implementation

• IFC2x3 - IFC2x Edition 3 - third release of the IFC2x Platform, published in Feb 2006, mainly quality improvement of IFC2x2

• IFC2x4 - IFC2x Edition 4 - forth release of the IFC2x Platform - several extensions of IFC in building, building service and structural areas, enhancements of geometry and other resource components,  and numerous quality improvements, and a new documentation format
• current version IFC2x4 Release Candidate 3 as of October 2011
• see IFC development roadmap for a detailed schedule of the IFC2x4 release developments

• IFC2x2-Add1 - IFC2x Edition 2 Addendum 1 - small addendum of IFC2x to fix issues that came up during implementation, published in Jul 2004
• this release has been used for IFC2x2 implementation and certification
• IFC2x2 - IFC2x Edition 2 - second release of the IFC2x Platform, published in May 2003, several extensions of IFC in domain areas
• IFC2x-Add1 - IFC2x Addendum 1 - small addendum of IFC2x to fix issues that came up during implementation, published in Oct 2001
• this release has been used for IFC2x implementation and certification

• IFC2x - IFC2x - first release of the IFC2x Platform, published in Oct 2000, focused on providing a stable platform

The older releases IFC2.0, IFC1.5.1, IFC1.5 and IFC1.0 are meanwhile outdated and are not any longer maintained.