Proteus PCB design - Proteus PCB design combines the schematic capture and ARES PCB layout programs to provide a...
Altium PCB Designer - Altium offers a top-notch, best-in-class PCB Designer to give engineers the tools they need to interlink with each side involved in the electronic design process.
Ktechlab - KTechLab is an IDE for microcontrollers and electronics.
Ngspice - Ngspice is a mixed-level/mixed-signal circuit simulator.
KiCad - A Cross Platform and Open Source Electronics Design Automation Suite
DipTrace - DipTrace - Professional Schematic Capture and PCB Design Software