QucsQucs is an open source integrated circuit simulator. The tutorial is just a simple DC simulation.
TutorialOpen up Qucs!
Select Components on the left tab.
Drag components you want.
Edit components properties by double clicking.
Select sources from drop down on top left.
Add DC voltage sources or DC current sources.
Complete the circuit by selecting wire on the top tool bar.
Select simulations from drop down on top left.
Add DC simulation.
Start simulation by clicking Simulation -> Calculate DC bias.