BRL-CAD is a powerful cross-platform constructive solid geometry solid modeling system that includes an interactive geometry editor, ray-tracing for rendering & geometric analyses, network distributed framebuffer support, image & signal-processing tools.
Earth orbits and satellite coverage display in 3D on your laptop.
SaVi - simulate Starlink, Iridium, Globalstar, O3b, GPS, Galileo and other satellite constellations, modify them, or design your own. Requires Tcl/Tk and Unix libraries; 3D viewing option requires Geomview running on X Window.
FrAid(FRactal AID) is an interface to Java, allowing it to proc. math. data(functions/equations). A compl. standalone system utilizing the FrAid prog. lang. is available(no need to be Java programmer to use it!). Use instead of Matlab. High res. graphics
SPE is a python IDE with auto indentation&completion,call tips,syntax coloring&highlighting,uml viewer,class explorer,source index,todo list,pycrust shell,file browsers,drag&drop,Blender support.Spe ships with wxGlade,PyChecker and Kiki.