OverTheWire: Wargames : The wargames offered by the OverTheWire community can help you to learn and practice security concepts in the form of fun-filled games.
WebScarab : WebScarab is a framework for analysing applications that communicate using the HTTP and HTTPS protocols.
Cilium : Cilium is open source software for providing and transparently securing network connectivity and loadbalancing between application workloads such as a...
Kali Linux : Penetration Testing Linux OS containing tools to test the security of system or a network.
A proposed standard which allows websites to define security policies.