The Guard component brings many layers of authentication together, making it much easier to create complex authentication systems where you have total control.
CrimeFlare is a useful tool for bypassing websites protected by CloudFlare WAF, with this tool you can easily see the real IP of websites that have been protected by CloudFlare. The resulting information is certainly very useful for conducting further penetration testing, and analyzing websites with the same server.
Security provides an infrastructure for sophisticated authorization systems, which makes it possible to easily separate the actual authorization logic from so called user providers that hold the users credentials. It is inspired by the Java Spring framework.
Fides is an SSH certificate signing server. It enables zero-trust infrastructure for your engineers by dynamically, and transparently, issuing short-lived certificates with clearly defined permissions.
Damn Vulnerable Web Services is an insecure web application with multiple vulnerable web service components that can be used to learn real world web service vulnerabilities.