OpenVAS (Open Vulnerability Assessment System) is a free alternative to the well-known Nessus vulnerability scanner. With the latest Nessus version, the licensing model changed and the latest plugins are only available to paying customers.
Based on Nessus 2.2, OpenVAS is deployed in the same way: a server is installed to perform checks against target(s) and is feeded with NVTs (network vulnerability tests) coming from the OpenVAS repository. Clients (GUI or batch) connect to the server to start tests and check results.
I’m still running Nessus server with the Inprotect front end. I’ll try to test OpenVAS asap and compare their results.