VirtualBox is a general-purpose full virtualizer for x86 hardware. Targeted at server, desktop and embedded use, it is now the only professional-quality virtualization solution that is also Open Source Software.
Some of the features of VirtualBox are:
- Modularity. VirtualBox has an extremely modular design with well-defined internal programming interfaces and a client/server design. This makes it easy to control it from several interfaces at once: for example, you can start a virtual machine in a typical virtual machine GUI and then control that machine from the command line, or possibly remotely. VirtualBox also comes with a full Software Development Kit: even though it is Open Source Software, you don't have to hack the source to write a new interface for VirtualBox.
- Virtual machine descriptions in XML. The configuration settings of virtual machines are stored entirely in XML and are independent of the local machines. Virtual machine definitions can therefore easily be ported to other computers.
* VMM: fixed recompiler crashes under certain conditions
* VMM: fixed running 64-bit guests on 32-bit host with nested paging enabled on AMD CPUs (4.0 regression)
* VMM: fixed timing issues / hangs for certain guests using the programmable interval timer
* VMM: large page and monitoring fixes for live snapshots
* GUI: fixed error message when trying to exceed the maximum number of host network interfaces
* GUI: fixed saving of changes to the metadata of an existing snapshot
* GUI: fixed rare crash on X11 hosts
* GUI: when selecting a shared folder, start the file dialog in the users home directory
* ExtPack: enforce the correct permissions which might be restricted by umask when creating directories (non-Windows hosts only)
* VBoxSDL: fixed crash when starting by specifying the VM UUID (4.0 regression)
* VBoxManage: allow savestate even if the VM is already paused
* VBoxManage: fixed modifyvm --synthcpu
* VBoxManage: fixed hang when doing guestcontrol execute –wait-for exit and displaying process status on exit
* VBoxManage: decreased CPU load during guestcontrol execute –wait-for exit/stdout while waiting for the guest process to terminate
* VBoxManage: fixed list hostdvds/hostﬂoppies
* VBoxManage: fixed storageattach for host DVD drives and host ﬂoppy drives
* Metrics: introduced RAM/VMM base metric.
* Main: improved sanity check when taking a VM screen shot
* Main: fixed a crash under rare circumstances if a VM failed to start
* Main: fixed attaching of immutable disk images
* Main: fixed a crash at VM shutdown
* Main: fixed incorrect handling of cross-referenced medium attachments
* Settings: fixed truncating of big integer values (4.0 regression)
* Settings: properly store the ICH9 chipset type
* Host-Only & Bridged Networking: fixed VBox DHCP server startup issue for Windows hosts (4.0 regression)
* Host-Only Networking: re-create vboxnetX interfaces after vboxnetadp.ko module reload on Linux and Darwin
* NAT: fixed an mbuf leak under rare circumstances
* ACPI: don’t allow the guest to enter S4 by default and don’t announce S1 and S4 in the ACPI tables if disabled
* Graphics card: made re-enabling disabled screens work correctly to prevent problems when X11 guests enter screen saving mode
* Storage: fixed write errors with snapshots if the host cache is disabled (4.0 regression)
* ATA/SATA: fixed reset handling after ACPI suspend/resume
* BusLogic: fixed hang with SMP VMs
* Serial: another attempt to prevent lost characters during transmission
* Linux hosts/guests: Linux 2.6.38-rc1 compile fixes
* Mac OS X hosts: fixed VBoxSVC crash when listing host interfaces without default gateway (64-bit hosts only)
* Solaris/Darwin hosts: fixed VM CPU execution cap
* X.Org guests: fixed a crash on X server restart
* X.Org guests: support X.Org Server 1.10 pre-release and Ubuntu 11.04 Alpha.
* X.Org guests: Add EDID emulation in the graphics driver to prevent GNOME settings daemon changing the mode on login.
* X.Org guests: never send graphics modes to the host that older VirtualBox versions can’t handle.
* Linux Additions: fixed a memory leak in the shared folders code if a host link is not readable
* Windows Additions: fixed handling of Security Attention Sequence (SAS) with VBoxGINA