So here we have good news for everyone that VMware has finally released a fully version of vSphere HTML5 Web Client and the official name will be vSphere Client. You may also call it "vSphere Client Fling".
You may download vSphere HTML5 Web Client Installer file from Here. However you will get it by default with vSphere 6.5 vCenter Setup.
Once you have deployed vCenter 6.5, you need to access https://<FQDN-or-IP-Address-of-VC>/. You will get both option
- vSphere Web Client,
- vSphere Client (HTML5)
Let's look insight how does it look and feel.