December saw the release of the latest major update to VirtualBox, Oracle's desktop virtualization tool. In its previous incarnation, it was voted as our readers' favorite virtualizer, so let's look at what 4.0 has to offer.
 

Upon launching the new VirtualBox, the first thing that becomes apparent is the new GUI layout. However, long-term VirtualBox users have little to fear as it remains a close relative of the original. The most obvious addition to the VM management part of the GUI is that there is now a thumbnail that gives a continuously updated view of a currently running GUI. It seems to have an update period of about once a second, so hopefully, it's not using up a lot of resources. Having said that, it's handy for people who just want to keep an eye on what's running.

Speaking of which, the VM windows themselves are now scalable. This means that you could have an OS running in, say, 1024x768 resolution but scaled to run in smaller window. Again, this is handy if you just want to keep an eye on things without sacrificing desktop space, and you can flip back to a full sized window with a key combination.

CLI junkie or GUI monkey? As with previous releases, VirtualBox 4.0 can be operated entirely via the GUI or from the command line, but the GUI continues to lag slightly behind in the case of some of the advanced features. For example, the new features of being able to set disk access bandwidth limits and the resizing of virtual hard disk images are only accessible via the command line. On the other hand, port forwarding now has a GUI dialogue. As some features are CLI only, it is important to have good documentation, and the good news is that the user manual has already been updated for the 4.0 features.

Under the hood, there have been some changes in the way that individual VMs store their settings. The settings file for each VM is now stored in the same directory as the HD image, and this, along with some other changes, makes transferring VMs between computers much easier. In addition, the file cleanup is more comprehensive when a machine is deleted.

Conclusion

Some may be disappointed with the volume of brand new features, given that this is a major version number change. What 4.0 offers over the most recent 3.x release is a new GUI and a few other improvements. A look through the release notes, makes it clear that there are a handful of smaller, although useful, new features in addition to the more noteworthy ones. I suspect that large minor version leap, from 3.2 to 3.5, would have given people a clearer idea of what the new release actually offers. However, this is a nitpick when we're talking about a such fine piece of free software as the OSE version of VirtualBox. Overall, it has some nice updates even though it lacks the earth shattering new innovations that people tend to expect from a full version number increment.