VMWare is one of the leading Virtualization products nowadays. Most recent versions are ESX and ESXi. VMware ESXi is a smaller footprint version of ESX that does not include the ESX Service Console. It is available without the need to purchase a vCenter license as a free download from VMware with some features disabled.
ALM4 supports both VMWare versions to ensure that users continue to benefit from Cisco Single Sign-on.