Welcome to the IFC Export for Revit Sourceforge project! This project contains the .NET code and DLL used by the Revit 2012-2014 families of products that support IFC export. The open source version can override the version that comes standard with shipped Revit.
The newest version is for R2014 and R2014 LT, and is based on R2014 RTM, but will take advantage of fixes included in UR1, especially for IFC4 support.
The base version of the R2013 code and is based on R2013 RTM, but will take advantage of fixes included in UR1 and UR2.
The base version of the R2012 code is based on R2012 UR1. The latest R2012 code is based on R2012 UR2. Any new customization projects should use the R2013 code instead of the R2012 code, unless it is specifically intended to work with R2012 only.
Revit Architecture, Structure and MEP are all certified for IFC2x3 Coordination View 2.0 Export as of v2.12.0 for 2013 and v3.4.0 for 2014. See [IFC Export Certifications] for the full history of certification.