The framework has three main parts. An API (needs a lot of work), a Web UI (kind of OK), and a Service (solid, small, runs and manages the Profiles and Scans). It is written in C# and ASP.NET, so it is cross platform (I develop on Linux using monodevelop). Most tools are in scripting languages too or are also cross-platform. Using PGSql as the DB backend and FluentNHibernate for persistence. In order to automate OpenVAS, Nexpose, Nessus, and Metasploit, I am using my openvas-sharp, nexpose-sharp, nessus-sharp, and metasploit-sharp bindings.
When you create a profile via the Web UI, the scan of the profile takes place in two parts, breadth and depth. First, the service gathers as much surface area of the host as possible. This is called the Profile phase. Once the host has been profiled and it's attack surface area figured out, we move onto the Scan phase, where we actively attempt to find vulns using the surface area we determined in the previous phase.
Current tools automated during the Profile phase are Nmap (in a few incarnations), Nikto, sslscan, onesixtyone, smbclient, and a few others off the top of my head, with more web fingerprinting and other tools in the pipeline (MBSA is one). smbclient will loop through each share it can find and attempt to log in anonymously (unless creds are provided) and attempt an "ls;recurse" which tells smbclient to list all files on the share. This phase can be considered mostly passive and can be run on it own with no Scan attached.
Current tools automated during the Scan phase are OpenVAS, Nexpose, Nessus, Metasploit/Pro, Wapiti, DSXS, and SQLMap. This phase is by far the most important and integrative. We use all the data collected in the previous profile to decide what to scan. By using as many vuln scanners like OpenVAS, Nexpose, and Nessus as possible, you can find far better results in terms of deducing false positives and false negatives (2 out of 3 report this, 33% chance false positive. 1 out of 3 report that, 66% chance false positive). This phase is laid out like a pyramid, with Metasploit on top. Before Wapiti and SQLMap are run, your vuln assessment scans are kicked off. As these run, we fuzz any known web services running that we know about with Wapiti (not just port 80 and 443, anything NMap decided was http). We take this XML report it creates (must run trunk) and parse it and figure out exactly what wapiti found and pass on the relevant details to SQLMap and DSXS to figure out exactly how to exploit any SQL injection or XSS vulnerabilities. I use some novel methods to ensure SQLMap only tests what Wapiti was found to find vulnerable, so it is pretty quick, and can be made quicker with a few tweaks. This requires a Profile to have been run.
In the end, the data from wapiti, openvas, nessus, and nexpose are fed into metasploit via sshfs mountint the remote /tmp locally. Then a metasploit pro discovery is done, then a quick bruteforce, then an exploit task is started using all the data from the previous scans. Once this is done, the scan phase is over and persisted and your results will be in the web UI.
Not all tools are required, if you don't have access to Metasploit Pro, you can simply choose to not run it. The same goes for OpenVAS, Nexpose, and Nessus. It is granular to that point. You may also choose to not run the web assessment, and only run the general vuln assessment(s).
Most of the data collected is presented in the UI in some form or fashion, but not all of it is. Installation isn't straight forward so please read the README.
Generally I run against: a vulnerable FreeNAS distro, Metasploitable2 with TWiki removed, BadStore, and a vulnerable Windows XP SP2 machine.
Please hit me up on IRC (bperry on Freenode, idle in #metasploit) if you have trouble setting up (you probably will, but I hope you don't!).