FreeBSD 9.1 is the second release from the stable/9 branch, which improves on the stability of FreeBSD 9.0 and introduces some new features. Some of the highlights: new Intel GPU driver with GEM/KMS support; netmap(4) fast userspace packet I/O framework; ZFS improvements from Illumos project; CAM Target Layer, a disk and processor device emulation subsystem; optional new C++11 stack including LLVM libc++ and libcxxrt; jail devfs, nullfs, zfs mounting and configuration file support; POSIX2008 extended locale support, including compatibility with Darwin extensions; oce(4) driver for Emulex OneConnect 10Gbit Ethernet card.