Due to a change of Nessus Licensing the online Nessus service has been discontinued. Nessus is a popular commercial vulnerability scanner that at one time was an Open Source solution. After a take over by Tenable and change of licensing the free use of plugins (or security checks) have been made unavailable for commercial use. During 2010 Tenable introduced an online scan service similar to what we have here at HackerTarget.com. Prices for the Nessus solution start at $995 for 1 month or $3600 for 1 year of access to the Nessus online Scanning tool, where as our prices are $89 for 12 months - including access to all of our scanning tools. There are some obvious differences to the two solutions and for many large companies the two offerings would complement each other as both an alternative audit capability and additional more focused scans we have at HackerTarget.com. However if you wish to run Nessus at home you can still access the full Nessus plugin feed for free. Go to the Nessus website and proceed to download and install the scanner for your system. Here is a guide for installing Nessus on Ubuntu. Using Nessus your internet host will be scanned and tested for thousands of vulnerabilities by the world class Vulnerability Scanning Solution. Including the Sans Top Twenty vulnerabilities.
OpenVas is a fork of the Open Source Nessus project that remains fully open source and is a becoming a leading vulnerability scanner. This is our primary vulnerability scanning solution; head over and get onto the Online OpenVas scan option.

NexPose is another similar offering from the people at Rapid7, owners and developers of the popular Metasploit Framework a powerful penetration testing tool.