Shodan - Shodan is the world's first search engine for Internet-connected devices.
HackerOne - HackerOne provides a platform designed to streamline vulnerability coordination and bug bounty program by enlisting hackers.
Vega - Subgraph Vega | Free and Open Source Web Application Vulnerability and Security Scanner
Acunetix - Audit your website security and web applications for SQL injection, Cross site scripting and other...
w3af - w3af is a Web Application Attack and Audit Framework
Trustwave Services - Trustwave is a leading cybersecurity and managed security services provider that helps businesses fight cybercrime, protect data and reduce security risk.