From Wiki.OSArch

IFC++ or IfcPlusPlus is a C++ open source (MIT license) library from the IfcQuery project for reading, writing, and viewing IFC files.

The IFC++ library can be used for general purpose, and it also includes a sample IFC visualization application. This viewer is based on Qt 5 and OpenSceneGraph (OSG), and can load big IFC files very fast, and thus can be used to compare the performance of other free IFC viewers, like Blender and FreeCAD, which internally use the IfcOpenShell library.


The IFC++ distribution is provided as source code, so to use the library and the sample viewer, the code must be compiled.

To learn more about installing IFC++, visit the page in the FreeCAD wiki: IfcPlusPlus.


  • The IFC++ distribution includes a sample viewer in source code that uses the IFC++ library, and that is compiled together with it.
  • A second viewer exists with the generic name of "IfcQuery", that uses pre-compiled IFC++, Qt, and OSG libraries, and is only available for Windows. This viewer is more complete than the sample viewer included with the source code of IFC++, but is not open source. It is free for use and available by downloading the SimpleViewerExampleQt.zip package from ifcquery.com, and running SimpleViewerExampleQt.exe. This viewer is self-contained, everything that it requires to run is included in the .zip archive.

Note: in common usage, the names "IfcQuery", "IFC++", and "IfcPlusPlus" may be used interchangeably to refer to the same thing, the C++ library or more specifically the IFC viewer.