A third-party extension is designed to be incorporated into ESX/ESXi in order to enhance, or extend, the functions of ESX/ESXi. For example, an extension might be a VMkernel module, a driver, or a CIM provider.

VMware provides the following tools for installing, removing, and updating extensions to ESX/ESXi hosts:

vSphere Host Update Utility

Graphical utility for ESXi only. See the Upgrade Guide.

vCenter Update Manager

For ESX and ESXi, automates patching and updating of extensions. See the vCenter Update Manager Administration Guide.

vihostupdate

Command-line utility for ESX and ESXi.

esxupdate

Command-line utility for ESX only. See the Patch Management Guide.