I had an old CD that was not playing on my cd player. Placing the cd in windows explorer, I found that the file types were .aiff (Apple's old format). Scouting for a converter that would convert from .aiff to .wav, I only found sharewares.
Scouting further, I found this project Audacity, an open source project that deals with music file converters. Nothing to pay - got the job done.
I use the open source GNU Dia to create diagrams like UML.
Then there is JBoss, Eclipse, Tomcat....
Hail Open Source!