I'm not saying it's impossible, it's just a lot harder than a desktop-app, because there isn't a GUI toolkit with standard look & feel, functionality, and API.

I'm not saying it's impossible, it's just a lot harder than a desktop-app, because there isn't a GUI toolkit with standard look & feel, functionality, and API. Web designers ultimately write one from scratch every time they need to create a new web app. IMO that's wrong. GWT is the only proper GUI toolkit I know, and it truly borrows lots from desktop APIs. But not everyone wants a 100% JS web page, some people still care about SEO.