Open source suite of SCAP tools
http://www.open-scap.org/page/Main_Page
SCAP is a line of standards managed by NIST. It was created to provide a standardized approach to maintaining the security of enterprise systems, such as automatically verifying the presence of patches, checking system security configuration settings, and examining systems for signs of compromise.
The SCAP suite contains multiple complex data exchange formats that are to be used to transmit important vulnerability, configuration, and other security data. Historically, there have been few tools that provide a way to query this data in the needed format. This lack of tools makes the barrier to entry very high and discourages adoption of these protocols by the community. It's our goal to create a framework of libraries and tools to improve the accessibility of SCAP and enhance the usability of the information it represents.