Solibri Model Viewer - Views Solibri Model Checker and IFC models on both Windows and Mac.
Tekla BIMsight - Tekla BIMsight is a leading Windows-based construction collaboration tool for construction industry professionals.
FZKViewer - FZKViewer visualises the sematic data models IFC, CityGML und gbXML
EcoDomus - EcoDomus is an all-in-one Building Information Management (BIM) software solution that offers lots of building improvement tools for real estate owners and tenants.
Tekla Structures BIM Software - Open approach to Building Information Modeling
usBIM.viewer+ - Do you need to open an IFC file and modify it? usBIM.viewer+ is the only freeware certified by buildingSMART International that allows you to view, edit, convert and share BIM models in the IFC format. Basically, it is more than just a viewer!