eG Innovation is a US company which produces a product called VM Monitor, able to merge and correlate performance data collected inside the virtual machines (on the guest OSes) and inside their virtualization host (both the VMKernel and the Service Console in case of ESX).
This approach greatly helps to have the big picture of the virtual infrastructure and pinpoint bottlenecks accordingly.
With the new version of the eG Enterprise Suite, which includes VM Monitor, the company introduces the capability to do agentless monitoring and the support for VMware ESXi and Sun Solaris Containers.
Additionally, eG Innovations plans to extend this support to Citrix XenServer later this year.
Pricing is per ESX server monitored and starts at at $50,000 for a 25-nodes VMware Infrastructure.