Review: VMware Workstation 9 vs. VirtualBox 4.2
VMware Workstation is richer in features and polish than ever, but VirtualBox is still both capable and freeFollow @syegulalp
Oracle VM VirtualBox 4.2
Right up front I'll say that VirtualBox, even in its newest incarnation, isn't a feature-for-feature match for VMware Workstation. It is, however, a very good way to get most of the core functionality of Workstation without paying the full retail price, especially if you're using the open source version. (The binary version of VirtualBox, which includes proprietary extensions such as USB 2.0 support, is free for personal use, but requires commercial licensing for professional deployment.)
The best way to distinguish the two programs is by a word I used a lot with VMware Workstation: polish. When VirtualBox has a feature also found in Workstation, most of the time it's Workstation's implementation of that feature that really shines.
Consider the VM setup process. In VirtualBox, this involves using a wizard that prompts you for which operating system you're going to be installing in the VM. However, it doesn't provide the kind of extended setup automation features that Workstation does. The wizard does set a recommended memory size for the VM and maybe a couple of other internal options, but the actual OS installation process still has to be done manually.
A new feature in VirtualBox is the ability to group VMs, even in nested groups, for the sake of organization.
The same sorts of things apply elsewhere. USB support in VirtualBox is limited to USB 2.0, whereas VMware Workstation can emulate USB 3.0. Also, while VirtualBox can connect to USB devices (such as cameras or scanners) on the host, it's far easier to get this feature working in VMware Workstation, and VirtualBox doesn't connect to and release hardware as reliably as VMware Workstation does.
In another vein: VirtualBox has a way to allow remote connections to VMs, but it uses a peculiar variation on Microsoft's Remote Desktop Protocol. It's rather odd that open source VirtualBox uses a twist on RDP, while the commercially licensed VMware Workstation uses VNC. (To be fair, the remote desktop support is one of VirtualBox's proprietary extensions.)
If VirtualBox has limitations like these, where does it shine? In lots of little ways, which do make up for many of its limitations. A given virtual machine can support up to 32 virtual CPU cores per machine, with the maximum depending on your host hardware's capabilities. On my test system (8 cores, 4 physical and 4 logical), VirtualBox exposed up to 16 for use with VMs. I also like the "execution cap" function, which lets you specify a hard limit for host CPU utilization -- a feature not explicitly provided by VMware Workstation.