ECAD stands for Electronic Computer-Aided Design and refers to Software that assists in transitioning Electronic Design to Electronic Manufacturing (Implementation). EDA stands for Electronic Design Automation and refers largely to ECAD but also encompases Design-specific tools (e.g. SPICE simulation, signal integrity simulation, digital timing/functional simulation tools, etc.)

The following is a great Venn Diagram indicating the overlap of this field with other Software tools: CAD Industry Diagram

Some free ECAD Sources:

  • Eagle PCB has been a freely available toolset for Schematic and PCB design
  • PCB123 - PCB design tools
  • KiCAD is an open-source project for Schematic and PCB Design
  • Fritzing is an open-source system drawing tool

Some free EDA Sources:

Not free, next EDA step up:

  • Altium tool suite is a smaller enterprise toolset. They've been partnering closer with Atmel (read:Arduino) recently…

Electronics Parts Search aggregators (For your Parts-finding needs):

Want to make your PCB/PWB (Printed Circuit Board/Printed Wiring Board)? Sources to spin your board:

Want to get your PCB populated into a PCBA(Printed Circuit Board Assembly)?: