Hello everybody! This is my first entry for this competition. Quite Universal Circuit Simulator (Qucs) is an libre software electronics circuit simulator software released under GPL. It gives you the ability to set up a circuit with a graphical user interface and simulate the large-signal, small-signal and noise behaviour of the circuit. Pure digital simulations are also supported using VHDL and/or Verilog. http://repo.openpandora.org/?page=detail&app=qucs Any feedback is welcome, and rates too, ejem, PD: I hope selected category isn't wrong.