You can download the binaries here.
Please do NOT open bug reports at http://www.virtualbox.org/wiki/Bugtracker but use our VirtualBox Beta Feedback forum to report any problems with the Beta. Please concentrate on reporting regressions since VirtualBox 3.2.12 / VirtualBox 4.0.0 Beta 2.
Note: As of version 4.0, VirtualBox introduces the Extension Pack mechanism which allows Oracle and 3rd parties to deliver additional functionality on top of the standard Open Source product. The Oracle VM VirtualBox Extension Pack, adds support for USB 2.0, RDP server and the PXE bootloader with E1000 support.
You can download this Pack from the same location and install it via the VirtualBox Global Settings using the Extensions pane.
This is the third beta of the upcoming 4.0 release. The following items were added/fixed since VirtualBox 4.0.0 Beta 2:
- Solaris hosts: another fix for installing ExtPacks on Solaris
- Solaris hosts: properly register mime types
- GUI: fixed a crash if maximizing a guest window is not allowed
- GUI: remember recent mounted mediums
- GUI: fixed additions mounting
- GUI: added hint how to get out of the scale mode
- GUI: fixed black fullscreen minitoolbar on KDE4 hosts (bug #5449)
- GUI: allow to update / downgrade / reinstall ExtPacks
- 3D support: fixed incorrect rendering for some d3d8/9 apps
- 3D support: fixed OpenGL support for 32bit apps on 64bit Windows XP SP2
- 3D support: fixed installation on Linux without DKMS
- 3D support: fixed OpenGL support for libMesa 7.9
- VGA: fixed crash when booting VMs with older additions
- OVA: allow individual files greater 8GB
- Storage: performance optimization by not using our own block cache for read-only mediums
- BIOS: implemented multi-sector reading, speeds up booting of certain guests (e.g. Solaris)
- VMM: fixed FreeBSD 8.1 boot hang for unrestricted guest execution with VT-x
- VMM: fixed performance regression for 32-bit SMP guests (VT-x + nested paging)
- VMM: fixed performance regression (VT-x with preemption timer only)
- VMM: improved fix for blocking NMIs triggered by active performance counters (Linux hosts in non-VT-x/AMD-V mode only; bug #7819)
- User Manual: Windows help file (.chm) is searchable again
- Windows Additions: fixed Windows 2000 guests (4.0.0 Beta 1 regression)
- Solaris Additions: fixed guest X11 drivers
- Solaris Additions: fixed unexpected termination of VBoxService
- Linux Additions: fixed xorg.conf patching for older Linux (3.2.12 regression)