VMM: fixed restoring 32-bit FPU state on 64-bit capable VMs and restoring guest FPU in raw-mode VMs (bug #12646; 4.3 regression)
GUI: properly restore normal/scale mode guest-screen size after exiting full-screen/seamless mode
GUI: mini-toolbar should provoke less artifacts/conflicts with 3D guest rendering
GUI: Mac OS X: Native full-screen multi-screen transition was able to blackout host-screens for nearly minute
GUI: X11: Modern window managers should now use native full-screen multi-screen mapping API
GUI: added extradata item for configuring the mouse capture behavior, see the manual for more information (bug #3506)
Storage: fixed a VBoxSVC crash when querying an iSCSI target with authentication configured (4.3.14 regression)
Storage: fixed a rare data corruption during reads if another allocating write is running concurrently and accesses the same range
Storage: fixed a rare crash for certain VHD images from other products
Storage: fixed a rare release assertion when using the AHCI controller
Floppy: fixed read errors and guest memory corruption when running under control of QEMM
3D: added experimental support for rendering on offline GPUs for Mac OS X host
3D: fixed white window appearing on entering FullScreen mode on OSX host
3D: fixed video recording support for 3D data regression (bug #13073)
3D: fixes for MS Office 2013 support
3D: several fixes
Bridged Networking: improved IPv6 support when bridging to a wireless interface
NAT: prevent internal DNS service from stuck in host-resolver mode when host was switched from one network to another one while host was sleeping (Mac OS X hosts)
NAT: preserve DF (if possible) and TOS when proxying outbound UDP datagrams (bugs #9440, #12309)
NAT: don't let multicast datagrams out (bug #7338)
NAT: fixed handling of large incoming UDP datagrams on Windows hosts (bug #12136)
NAT: fixed handling of the RFC 1533 DHCP PAD option
NAT Network: fixed inbound half-close on Windows hosts
NAT Network: preserve IPv4 DF (if possible), TTL, TOS and IPv6 Hop Limit when proxying outbound UDP datagrams
VRDP: fixed a rare crash when using remote audio input
USB: fixed several regressions from 4.3.14 (bug #13320)
Audio: made the HDA sound emulation work with certain OSX guests (e.g. Mountain Lion)
Windows hosts: fixed startup problems on certain Windows hosts due to conflicts with anti-virus software (4.3.14 regression, bug #13187)
Windows hosts: fixed 4.3.14 regression whereby AltGr stopped working for some people (bug #13216)
X11 hosts: made the extra key on Brazilian Thinkpads work (bug #8745)
X11 hosts: fixed a problem of input focus cycles and immediately released key presses in full screen mode (bug #13238)
Linux hosts: fixed flooding the kernel log with USB related messages when passing through certain USB devices to a VM (bug #13085)
Linux guests: stop applications crashing when drm_wait_vblank is called (bug #13265)
Linux guests: fix a crash in gnome-session (bug #13335)
X11 guests: do not start VBoxClient over an SSH connection (bug #13107)
X11 guests: added support for X.Org Server 1.16 (bug #13207)
X11 guests: fixed a wrong parameter in the video driver which caused problems with full-screen X11 clients (bug #2748)
VirtualKD: introduced stub/loader device for speeding up Windows kernel debugging, details see http://virtualkd.sysprogs.org/
VirtualBox 原先是德国一家软件公司InnoTek所开发的虚拟系统软件（已被SUN收购，而SUN已被Oracle收购），它不仅具有丰富的特色，而且性能 也很优异。VirtualBox 可以在 Linux 和 Windows 主机中运行，并支持在其中安装 Windows (NT 4.0、2000、XP、Server 2003、Vista)、DOS/Windows 3.x、Linux (2.4 和 2.6)、OpenBSD 等系列的客户操作系统。假如你曾经有用过虚拟机软件的经历的话，相信使用 VirtualBox 不在话下。即便你是一个新手，也没有关系。VirtualBox 提供了详细的文档，可以助你在短期内入门。
