Nmap - Nmap Free Security Scanner, Port Scanner, & Network Exploration Tool. Download open source software for Linux, Windows, UNIX, FreeBSD, etc.
Qualys - Qualys helps your business automate the full spectrum of auditing, compliance and protection of your IT systems and web applications.
Advanced IP Scanner - Advanced IP Scanner shows all network devices, gives you access to shared folders, and can even remotely switch computers off. Download it Free.
Burp Suite - Burp Suite is an integrated platform for performing security testing of web applications.
Angry IP Scanner - Open-source and cross-platform network scanner designed to be fast and simple to use
OpenVAS - The Open Vulnerability Assessment System (OpenVAS) is a framework of several services and tools...