VirtualBox 3.1, a major update of Sun x86 virtualization software has been released and includes many improvements and bug fixes like:

• Teleportation (aka live migration); migrate a live VM session from one host to another (see the manual for more information)
• VM states can now be restored from arbitrary snapshots instead of only the last one, and new snapshots can be taken from other snapshots as well (”branched snapshots”; see the manual for more information)
• 2D video acceleration for Windows guests; use the host video hardware for overlay stretching and color conversion (see the manual for more information)
• More flexible storage attachments: CD/DVD drives can be attached to an arbitrary IDE controller, and there can be more than one such drive (the manual for more information)
• The network attachment type can be changed while a VM is running
• Complete rewrite of experimental USB support for OpenSolaris hosts making use of the latest USB enhancements in Solaris Nevada 124 and higher
• Significant performance improvements for PAE and AMD64 guests (VT-x and AMD-V only; normal (non-nested) paging)
• Experimental support for EFI (Extensible Firmware Interface; see the manual for more information)
• Support for paravirtualized network adapters (virtio-net; see the manual for more information)

Moreover, VirtualBox 3.1 offers a 30 percent improvement in memory handling over its previous version, upgraded network performance that offers better throughput and reduced CPU cycles through a new high-speed, paravirtualized network driver, and a new two-dimensional video acceleration feature for Windows VMs. It also includes better snapshotting features, according to Sun officials.

VirtualBox 3.1 is available to download for free and it runs on Windows, Mac OS X, Linux and Solaris hosts.