FreeCAD - An open-source parametric 3D modeler
Fritzing - Fritzing is an open-source initiative to support designers, artists, researchers and hobbyists to...
SolidWorks - Dassault Systèmes SolidWorks Corp. develops and markets 3D CAD design software, analysis software, and product data management software. SolidWorks is the leading supplier of 3D CAD product design engineering software.
Proteus PCB design - Proteus PCB design combines the schematic capture and ARES PCB layout programs to provide a...
LibreCAD - An open source 2D CAD application for Windows, Apple and Linux.
LTspice - LTspice® is a high performance SPICE simulation software, schematic capture and waveform viewer with enhancements and models for easing the simulation of analog circuits.