Electronic schematic and PCB design software

 Kicad is a suite of programs for the creation of printed circuit boards.
 It includes a schematic editor, a PCB layout tool, support tools and a
 3D viewer to display a finished & fully populated PCB.
 .
 Kicad is made up of 5 main components:
 .
  * kicad - project manager
  * eeschema - schematic editor
  * pcbnew - PCB editor
  * gerbview - GERBER viewer
  * cvpcb - footprint selector for components
 .
 Libraries:
  * Both eeschema and pcbnew have library managers and editors for their
    components and footprints
  * You can easily create, edit, delete and exchange library items
  * Documentation files can be associated with components, footprints and key
    words, allowing a fast search by function
  * Very large libraries are available for schematic components and footprints
  * Most components have corresponding 3D models