Information:
Mops is a 3D modeling environment written in C with Tcl/Tk. It features:
RIB export
Support for NURB curves and surfaces, Boxes, Quadrics and CSG
Support for custom objects that may freely implement their representations
Support for small GUIs
Mops also has support for an arbitrary number of modeling views, clipboards, independent property clipboards, consoles and an advanced hierarchical browser.