New Technology to Replace JavaScript in WEB Browsers [on hold]

I would like to discuss the pros and cons of current WEB technologies and JavaScript. My understanding is that the WEB technologies is constantly improving. I would say that the following are the features to be extended:

• Java Script compatibility across browsers.
• Each web page in a browser is single threaded which is major restriction.
• Development/Deployment complexity versus Desktop Application.
• Communication mechanisms between the front-end and back-end.
• There is no solid architecture behind the WEB page. So it allows coding inside the HTML in a very custom manner. Which causes issues with backward compatibility.

Could you please come up with your point of view and with your expectations about the web technologies improvements. Especially is there a need to extend the JS and if yes, what are the things you would like to see improved?