Sun rev's "open source" desktop VM manager

Though boasting a seemingly minor release number (2.1), the new VirtualBox represents a major release, according to the changelog. However, many of the most significant new features are still described as "experimental." The changelog calls out new features that include:

• Support for hardware virtualization (VT-x and AMD-V) on Mac OS X hosts
  
  
• Support for 64-bit guests on 32-bit host operating systems (experimental)
  
  
• Added support for Intel Nehalem virtualization enhancements (EPT and VPID)
  
  
• 3D acceleration via OpenGL (experimental)
  
  
• LsiLogic and BusLogic SCSI controllers (experimental)
  
  
• "Full" VMDK/VHD support including snapshots
  
  
• New NAT engine with "significantly better" performance, reliability and ICMP echo (ping) support
  
  
• New Host Interface Networking implementations for Windows and Linux hosts with easier setup (replaces TUN/TAP on Linux and manual bridging on Windows)

is a graphical tool for managing virtual machines on the desktop. It lets users create and manage one or more "virtual machines," on which various x86 operating systems can be installed and run.

As in the past, VirtualBox 2.1 targets both users and developers. It lets users run favorite software, Sun says, while enabling developers convenience when building, testing, and running "cross-platform, multi-tier applications." It does this by enabling development and target systems to share a single physical host. Supported target "platforms" include Linux, OpenSolaris, Solaris, Windows, and Mac OS X.