This doesn't seem to be a Performance question to me. Moving to the Tools forum...
The soul is dyed the color of its thoughts. Think only on those things that are in line with your principles and can bear the light of day. The content of your character is your choice. Day by day, what you do is who you become. Your integrity is your destiny - it is the light that guides your way. - Heraclitus
Actually I am interested in an Open Source code coverage tool too. I have IntelliJ IDEA, and there is a code coverage plugin, but it is not free. I could use a standalone app.