HTML5 Multiplayer Game Engine

I am looking to have our client game ported to the web via HTML5. See the client at: [login to view URL] .The client is just a MDI based application that communicates to the server via packets and displays various information in controls. Our summer project (which includes this project post) is to port this client to the web along with major improvements to usability and gameplay. It is to be assumed we would like to avoid a websocket system, unless necessary, and instead leverage RIA. See the requirements below: Requirements: The canvas should be ultimately an isometric 2D engine interface, similar to what you have if you used RPGMaker. The map/functionality is similar to gaia online's zOMG or Towns App except there will be many avatars that will interact on a map. Clicking on another person would bring up a separate group of icons around the player to chat, look up, or other player to player related events. It must be able to have multiple maps (like towns/dungeons) and allow for multiple instances of the same map with different names (such as players can join a dungeon but if another player joins the same dungeon, it is a separate instance). The engine must allow for particles effects emanating from the avatar. It would be helpful if those particles could be drawn from a single image base so that we have an infinite capability of drawing particles. Players can interact with objects and some objects may be visible to only select players (avatars) on the map. When the player mouses over certain objects, it will glow and/or do certain events such as popup message boxes or initiate games. Chat functionality must be considered. Either through the database or through a tool to leverage mIRC. All code outerward facing/downloadable to the client must be obfuscated. There are a few extra details and examples that I will provide but only after the first screening because we do not want all of the project information open to the public.