What is "powercli"

PowerCLI is a Windows PowerShell interface for managing VMware vSphere.

VMware describes PowerCLI as "a powerful command-line tool that lets you automate all aspects of vSphere management, including network, storage, VM, guest OS and more. PowerCLI is distributed as a Windows PowerShell snapin, and includes over 370 PowerShell cmdlets for managing and automating vSphere and vCloud, along with documentation and samples."