Have you ever needed to document how secure your ESX servers are.

If the answer is yes then take a look at these free fools (Compliance Checkers) from ConfigureSoft.com.
http://www.configuresoft.com/compliance-checker.aspx

If the answer is no I would sugest you took a look at the tools anyway……

Compliance Checker for VMware ESX, checks the compliance of VMware ESX hosts against VMware hardening guidelines and Center for Internet Security (CIS) benchmarks.

Compliance Checker for PCI DSS, checks the compliance of servers and desktops against PCI DSS v1.2 requirements as specified by PCI Security Standards Council.