If you've been following the slides, you've probably been using our VMPlayer hack to run virtual machines on your desktop. I say hack because VMPlayer was intended to just run virtual machine prepared by other people. It was never intended to be used to create virtual machines like we do (as evidence by having to hand hack the config files for the virtual machines). VirtualBox, on the other hand, is under the GPL license and it IS intended to be used to create, manage and run virutal machines. It is effectively the equivalent of the VMWare Workstation product (except open source and free as in beer). One of the biggest reasons to favor the open source products over the closed source ones is that if updates happen in the operating system(s) that possibly change the way the product works, the open source community can submit changes to the product that maximize the compatibilty between the product and the operating system(s). Another benefit of sticking to the open source products is that at any time the open source community can branch the product's code to create exactly what they want if the company is not responding to community requests.

I'm not trying to tell you not to use VMPlayer at all. If it works well for you, keep using it. I do want to promote the use of the open source alternatives though.