On May 18th VMware announced the end of the road for the C# vSphere Thick Client. The next version of vSphere the thick client will not be available. VMware has been building up to this moment and previously announced they wanted to move to a web based client to have maximum compatibility and mobility. VMware has jettisoned the thick client in favor of the thin client with the HTML5 Web Client, removing Flash-related vulnerabilities and adding functionality. Share this item with your network: Stuart Burns. VMware’s release of vSphere 4.0 provided customers with the option to use either Thick or Thin Provisioning for virtual machine disks. With the release came debates on which version to use, along with the pros and cons of each.