Tenable is described as 'Delivers continuous IT security monitoring, compliance assessment, vulnerability detection, asset discovery, and collaborative management across cloud and on-premises environments' and is a IP Scanner in the network & admin category. There are more than 10 alternatives to Tenable, not only websites but also apps for a variety of platforms, including Windows, Linux, Mac and SaaS apps. The best Tenable alternative is Nmap, which is both free and Open Source. Other great sites and apps similar to Tenable are Angry IP Scanner, Zenmap, NetPeek and Advanced IP Scanner.