FreeCAD - An open-source parametric 3D modeler
CODESYS - CODESYS - the IEC 61131-3 programming system.
SketchUp - 3D for Everyone
RobotStudio - RobotStudio increase the profitability of your robot system by letting you perform tasks such as training, programming, and optimization
LibreCAD - An open source 2D CAD application for Windows, Apple and Linux.
ETAP - ETAP is a full spectrum analytical engineering software company specializing in the analysis, simulation, monitoring, control, optimization, and automation of electrical power systems.