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.
Guest Additions for Windows, Linux and Solaris.
VirtualBox has special software that can be installed inside Windows, Linux and Solaris virtual machines to improve performance and make integration much more seamless. Among the features provided by these Guest Additions are mouse pointer integration and arbitrary screen solutions (e.g. by resizing the guest window). There are also guest additions for OS/2 with somewhat reduced functionality.
Like many other virtualization solutions, for easy data exchange between hosts and guests, VirtualBox allows for declaring certain host directories as "shared folders", which can then be accessed from within virtual machines.
This is a maintenance release. The following items were fixed and/or added:
- VMM: fixed a potential misbehavior after restoring the A20 state from a saved state
- GUI: fixed full-screen mode mini-toolbar related regressions for different platforms and window managers (bug #13369)
- GUI: X11: fixed full-screen mode Unity panels quirk caused by mini-toolbar code changes in last release (bug #13365)
- GUI: X11: added possibility to use legacy full-screen mode as the new one can cause multi-screen issues under Unity, see the manual for more information (bug #13365)
- GUI: Mac OS X: fixed full-screen mode artifact causing black screen when 3D acceleration was enabled on 10.10 Yosemite hosts (bug #13448)
- GUI: Mac OS X: fixed regression in user-space swiping from/to VBox in full-screen mode
- GUI: Mac OS X: fixed issue with switching to VBox in full-screen mode through Alt+Tab and Mission Control
- Storage: fixed data corruption when resizing huge VHD images under certain circumstances (bug #11960)
- Storage: fixed a rare hang during startup when the BIOS enumerates the storage devices attached to the SATA controller
- Storage: follow the spec with AHCI interrupt acknowledge (bug #13474)
- Storage: fixed broken iSCSI authentication (4.3.14 regression, bugs #13386, #13435)
- NAT Network: properly parse port forwarding rules to allow UDP rules
- USB: fixed a crash on Linux hosts with older Linux kernels (bug #13400) and several other fixes
- ACPI: fixed ACPI timer anomalies (bug #12076)
- Guest Control: fixed a memory leak (bug #13434)
- Main: when removing a VM, do also remove the VBoxStartup.log file which might exist on Windows hosts (bug #13478)
- Windows hosts: fixed more startup problems on certain Windows hosts due to conflicts with anti-virus software; better error reporting (4.3.14 regression; bug #13187)
- Windows hosts: propagate the process startup information to the child process (4.3.14 regression; bug #13243)
- Mac OS X hosts: don't force using the discrete GPU (bug #11111)
- Windows Additions: some Windows 10 tweaks
- X11 guests: fix a bug handling video driver display properties which prevented GNOME Shell on Fedora 21 from starting
- Linux hosts / guests: fixed a few remaining warnings in the kernel log if memory allocation fails (bug #11171)