Trying to protect your expanding virtual machine (VM) empire will require a security product that can enforce policies, prevent VMs from being terminated or infected, and deliver the virtual equivalents of firewalls, IPS and anti-virus solutions.

We last looked at this product category nearly three years ago, testing five products. At that time, we said that no single product delivered all the features we desired. That’s still true today even though the market matured some. This time around we tested three vendors who were in our previous test — Catbird, Hytrust and Trend Micro – plus a newcomer, Dome9. All represent solid approaches to improving your VM security, but coming from different places.

Sadly, I wasn’t able to test lots of other VM security technologies, which I have listed here.

You can read my review of these VM security products for Network World here. And you can view a series of screenshots of the four products here.