Buildware 3D
Buildware 3D is a Windows CAD modeler software from the early 2000s written in C++ and based on the OpenCASCADE engine and OpenGL. Has 2D/3D modelling environment for interactive construction of geometry primitives, coordinate systems, layers, snapping, print layouts, property list UI. Heavy use of COM (the predecessor of .NET). Has a small core and modular design for high flexibility and extensibility through a custom plug-in framework based on COM interfaces. I was a member of the team of 3-5 developers.
Environment: Visual C++, MFC, COM, ATL, IDL, WinAPI, GDI, OpenGL, OpenCASCADE, Prof-UIS.