Qemu Network Tunneling...?
While doing some things at work, I reviewed "Network tunneling with... QEMU?" by Secure List where QEMU is used for network tunneling similar to netcat, socat, or other utilities.
networking
Network Fuzzing through Mutiny Fuzzing Framework
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.