Hey Steve, The reason that you are unable to reach the Free Version of ESX is due to the lack of activation as stated by Alpesh and Bill. That is the high level answer, here is a little more detail. The API is not available until the license is activated and the feature is enabled. By default the feature is disabled. The API accepts SOAP calls which is how the beacon connects to the vCenter/ESX host. This will not change unless VMWare enables this feature by default. RVTools uses the VI SDK to access data on vCenter/ESX hosts. This is very similar to the API as it is able to be used to execute remote commands, queries, etc. Yet it is an internal component of vCenter/ESX hosts and therefore is called differently. There are less limitations while using RVTools and therefore is more invasive during queries. Additional information on these components can be found here. http://www.doublecloud.org/vmware-vsphere-api-and-sdk-faq/ Hope this helps. Thank you, Ron Ziedman ... View more