There are plenty of virtualization security vendors leaping out of the shadows. Here are five new players worth a look.

Altor Networks. This company's Virtual Network Security Analyzer and Virtual Network Firewall (available later this year) aim to help gain visibility, increase control, and better secure virtual environments. Many of its executive team are from network firewall giant Check Point Software Technologies.

Fortisphere. This vendor provides an operational life cycle management product, called Virtual Insight, that enables enterprises to inspect, tag, track, and report on all virtual machines as they move throughout preproduction and production environments.

Reflex. This old-school IPS vendor has re-invented itself as a virtualization security vendor. The company's software can apply multiple network security and policy enforcement controls to protect virtual machines, virtualized networks, and the underlying host and virtualization platform.

Catbird Networks. Its HypervisorShield purports to protect the hypervisor management network from unauthorized access. The company also provides what it calls a VMware Hypervisor specific intrusion detection/prevention system for the virtual subnet -- so all of you out there routing virtual traffic out to your physical wire may not have to play such gymnastics any more.

Montego Networks. The company says its new HyperSwitch integrates network policy enforcement and access control into this virtual switch. The vendor boasts a number of capabilities, from policy-based virtual network partitioning (this can be a big deal in regulated environments) to policy-based switching and load balancing.

I'm looking for more virtualization security vendors. If you've knocked around a solution you've found helpful (or not so helpful), I'd like to hear about it.