Seamless mode is now also available for Linux and Solaris guest systems. In this mode, individual applications on the virtual machines can be launched normally on the desktop and are embedded in the host system's default window layout.
Virtualbox now includes SATA hard disk controllers and supports PAE (Physical Address Extension). Thanks to this extension 32 bit processors can address far more RAM. The integrated DHCP server now supports DHCPNAK. Virtualbox also includes a Webservice API and improved support for Linux kernel version 2.6.25. The Changelog has more details on the changes.

The new version can be downloaded either from the trunk, as a binary version, or as an Open Source Edition (OSE) with source code. It is little surprise that the software resides on Sun's website, considering the fact that Innotek, the company behind Virtualbox, was recently acquired by Sun.