There's been a lot of maturing of technology for FreeBSD 10 - lots of new features which make this release the most exciting one in years. Here are some of my personal highlights.
There's been a lot of development in the field of virtualization. FreeBSD has almost neglected "full" virtualization technology (relying on home-brewed jails/vnet), which made it a poor choice for modern deployments, but that is about to change. New stuff which will (probably, but nothing's certain) see the light of day in FreeBSD 10 is:
- bhyve - the native BSD hypervisor; it will be able to run at least the FreeBSD kernel fully virtualized, and possibly (please donate, or help to make this happen) also other generic operating systems;
- virtio drivers - developed alongside byhve; the drivers will be in the GENERIC kernel which will make it usable out of the box with any hypervisor supporting this interface - including, but not limited to, byhve, KVM and VirtualBox; the virtio drivers support PCI, memory balloon, network, block and (probably) SCSI interfaces;
- vmware vmxnet driver - will probably find its way into GENERIC, similarly enabling FreeBSD for better performance under VMWare;
- lots of enhancements and fixes to Xen and VNET systems (sorry, still no Xen Dom0)
In addition to these, I'd like to also mention:
- ZFS TRIM support;
- A truly tickless kernel, enhancing battery performance on laptops and general resource effectiveness in virtual machines;
- The NetMap framework for high-performance raw Ethernet packet access;
- Finally, an on-line growfs for UFS;
- FUSE driver in GENERIC, enabling the use of a large collection of user-space file systems developed for Linux;
- LLVM/Clang becomes the default compiler;
- Support for robust, remote/distributed security auditing;
- pkgng - the new package manager;
Stay tuned and watch the What's new wiki page for other updates!