This should be an interesting entry in light of the recent developments in the roadmap of both Fedora & openSUSE where MySQL is being ditched for MariaDB. This will affect new enterprise deployments in the next 18-24 months when the changes cascades into the next major release of RHEL & SLES.
At the heart of these changes is the perceived lack of openness & transparency of commercial juggernauts shepherding open source projects. Another example is LibreOffice, being a fork of OpenOffice a few years back, and is now the default in openSUSE distributions.
VirtualBox was originally from Innotek GmbH and they were acquired by Sun Microsystems Inc. in February 2008 which in turn got acquired by Oracle Corporation in January 2010. Virtualbox is not shipped as a default on openSUSE but you can install it very easily because the binaries are available in the default online repositories.
Personally, I think VirtualBox is the 'BEST' virtualization software for the desktop. I would go with KVM or even Xen for enterprise server virtualization. However, for virtualizing Windows or Linux on a desktop for quick testing purposes, I'll pick Virtualbox anytime for its ease of use & free of cost attributes.
Easy Install Method