I've been an avid user of VirtualBox for a long time! Much of what I've learned in my career had something to do with VirtualBox. I do all my testing and new tutorials in VirtualBox, I use Hortonworks Sandbox VirtualBox image for my work. This is probably not a new feature but it is definitely new to me because I just noticed it, VirtualBox has an option to run in different modes, at least from the GUI perspective. I know there's a lot of untapped potential in using the VBox CLI but I haven't had much need for it yet. Back to the topic, you can now launch your VMs in headless and detached modes right from the GUI! Usually, when I launch a VM in normal way, the VM window just hangs there and is pretty annoying. I prefer to SSH to a running VM from a console instead of using the VM window. Now I can launch a VM in headless mode and it's business as usual. No extra windows, and I bet the memory toll on my machine is also smaller. When you click on start your VM, you now have a drop down with three different options. I need to find out how to make headless start a default!