See http://lwn.net/Articles/2376/ . According to LWN (and other websites which have taken LWN as a source), there may be a patent-time bomb affecting SELinux: Secure Computing Corporation, who wrote a significant part of SELinux, holds patents on it, but doesn't give a clear-cut license, only a retractable statement that they don't intend to sue anybody except a few usage classes. -- Lionel