FreeBSD 11.0 Beta 4 is yet another small development snapshot that only addresses some issues discovered or reported by users since the previous Beta release, as well as to implement a handful of new features and update existing components. For example, the mtx_trylock_spin kernel synchronization primitive has been added, the newly implemented system hardening options have been improved to no longer overwrite existing ones that are selected by the user during installation, and it looks like the iwmfw and iwm drivers were updated again.