@xme posted an interesting dilemma on the SANS ISC InfoSec Forums contained within the post titled The Challenge of Managing Your Digital Library. He asked what seems like a simple question: "How do you manage your digital library on a daily basis?"
Fuzzing provides a way to test for vulnerabilities through generating random data to push into an application. This can be used to test desktop applications, network applications, and just about anything else.
pfsense probably is the most well-known used used open-sourced Linux firewall appliance in used today. It provides an easy to use web page GUI and installation is extremely easy.