Cloud Party has been available for the last year or so and I tried it out when it first appeared. Since, initially, Facebook linked login was required, and I long ago ditched Facebook due to its constant creep on privacy settings, I was only willing to create a “guest” avatar at the time which did not allow for appearance persistence or the use of a “home” virtual 3D space. That’s changed and several log in mechanisms are now available with Cloud Party.
Cloud Party gives a good indication of what might be possible with web-based 3D viewers based on WebGL – see this Blog Post at New World Notes for more information.
Visit my (underdeveloped) Cloud Party Home Space at https://a.cloudparty.com/went/SDAZmIVAR. And a shared Moonbase Alpha Space is available for trial building and to meet others at https://a.cloudparty.com/went/Soytosatz
Cloud Party Pictorial Inventory
Unity3D and Smart Fox Pro
Another possibility for browser based delivery of multi-user virtual worlds is Unity3D, along with the Smart Fox pro multi-user server library. Our OpenVCE environment in OpenSimulator exported and converted to a 3D model via Tipodean model conversion service – http://openvce.net/opensim-to-unity3d-via-tipodean-converter