This site is meant to be used as a tool for users of open source and sometimes commercial software who must keep constant track of new security bugs as soon as they appear in the wild. In its current state it constantly scans a number of security focused mailing lists for posts matching your criteria.
System Administrators who manage web based software are the primary audience for this tool, although it may be useful for anyone who wishes to keep track of 0-day advisories in their own hosted applications.