Pspice - OrCAD PSpice technology provides the best, high-performance circuit simulation to analyze and refine your circuits, components, and parameters before committing to layout and fabrication
LibrePCB - LibrePCB is a free EDA software to develop printed circuit boards.
Oregano - oregano - An electrical engineering tool for GNOME
XCircuit - XCircuit: Home Page
Solve Elec - Solve Elec is a free educational program to draw and analyze electrical circuits.
KiCad - A Cross Platform and Open Source Electronics Design Automation Suite