Asymptote is a powerful descriptive 2D and 3D vector graphics language for technical drawing, inspired by MetaPost but with an improved C++-like syntax. It provides for figures the same high-quality level of typesetting that LaTeX does for scientific text. Asymptote is a programming language as opposed to just a graphics program. It can exploit the best features of script (command-driven) and graphical user interface (GUI) methods. High-level graphics commands are implemented in the language itself, allowing them to be easily tailored to specific applications.
pythonOCC is a 3D CAD/PLM development library for the Python programming language. It provides 3D hybrid modeling, data exchange (support for the STEP/IGES file format), GUI management support (wxPython, PyQt, python-xlib), parametric modeling, and advanced meshing features. pythonOCC is built upon the OpenCASCADE 3D modeling kernel and the salomegeom and salomesmesh packages. Some high level packages (for parametric modeling, topology, data exchange, webservices, etc.) extend the builtin features of those libraries to enable highly dynamic and modular programming of any CAD application.