CircuitMaker
CircuitMaker is the best free PCB design software by Altium for Open Source Hardware Designers, Hackers, Makers, Students and Hobbyists. From the about page of the website:
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Open-source initiative aiding designers, artists, and researchers in transforming prototypes to actual products, documenting circuits, sharing, teaching, and PCB manufacturing.
TinyCAD
TinyCAD is an open source schematic capture program for MS Windows. Use TinyCAD to produce professional circuit diagrams and export net list information to PCB applications.