OpenSSL - OpenSSL is a free and open source software cryptography library that implements both the Secure Sockets Layer (SSL) and the Transport Layer Security (TLS) protocols, which are primarily used to provide secure communications between web browsers and …

Exploit Pack - Exploit Pack is an open source project security that will help you adapt exploit codes on-the-fly.

Let's Encrypt - Let’s Encrypt is a free, automated, and open certificate authority brought to you by the Internet Security Research Group (ISRG).

ZoomEye - Network mapping service

Authy - Best rated Two-Factor Authentication smartphone app for consumers, simplest 2fa Rest API for developers and a strong authentication platform for the enterprise.

Armitage - Armitage makes penetration testing easy by adding a GUI to the Metasploit framework