Bentley is described as 'Architecture is an advanced, yet intuitive and easy-to-use architectural building information modeling (BIM) application that empowers architects and designers to create with unlimited freedom' and is a 3D Modeler in the photos & graphics category. There are more than 25 alternatives to Bentley for a variety of platforms, including Windows, Mac, Linux, Web-based and iPhone apps. The best Bentley alternative is LibreCAD, which is both free and Open Source. Other great apps like Bentley are Autodesk AutoCAD, SOLIDWORKS, DraftSight and Microsoft 3D Builder.