VMware vSphere Update Manager PowerCLI 6.0 was available to download from the developer's website when we last checked. We cannot confirm if there is a free download of this software available. We recommend checking the downloaded files with any free antivirus. The following versions: 6.0, 5.5 and 5.1 are the most frequently downloaded ones by the program users. This free software is a product of VMware, Inc.
From the developer:
The VMware vSphere Update Manager PowerCLI provides a set of cmdlets for downloading software patches, creating and modifying baselines, and for scanning and remediating virtual machines or hosts. These cmdlets are stored in the VMware.VumAutomation plug-in, and are available through the VMware vSphere PowerCLI console.
You may want to check out more software, such as VMware vSphere Client, NetApp Virtual Storage Console for VMware vSphere or Portlock Windows Update Manager, which might be related to VMware vSphere Update Manager PowerCLI.