OpenSCAD is a software for creating solid 3D CAD models. It is free software and available for Linux/UNIX, Windows and Mac OS X. Unlike most free software for creating 3D models (such as Blender) it does not focus on the artistic aspects of 3D modelling but instead on the CAD aspects. Thus it might be the application you are looking for when you are planning to create 3D models of machine parts but pretty sure is not what you are looking for when you are more interested in creating computer-animated movies.
QCAD is a free, open source application for computer aided drafting (CAD) in two dimensions (2D). With QCAD you can create technical drawings such as plans for buildings, interiors, mechanical parts or schematics and diagrams. QCAD works on Windows, Mac OS X and Linux. The latest release 3.6.0 comes with following updates Save block visibility when saving to DXF/DWG Show measured value of dimension entities Improved handling of block references with attributes New entity type ‘XLines’ (infinite lines, construction lines) New entity type ‘Rays’ Option to choose if constructed lines should be line segments, infinite lines or rays Support alternative path for configuration files (command line switch -config [path]) Restrict angle to multiples of given angle Restrict distance to multiples of given distance New tool ‘merge’ to merge multiple CAD files into one drawing, based on an XML input file Fix permission problem with log files created by command line tool batch files (Isometric) projection: poor preview performance Property editor: read only text entity property editable through context menu Text editor: handling of non-breaking space (\~, ) Break out segment: fails in some cases Install QCad 32bit OS wget https://www.