An ideal situation would be installable interpreters that still allowed you to use a system-wide rendering engine. I actually think Windows had something similar with ActiveScripting.
I assume something like QT allows you to script the webview with whatever language you have bindings for? Unfortunately QT+bindings is a pretty long way from 'zero install'
Sounds more like plugin hell to me. I think it's becoming increasingly harder to convince users to install browser plugins (for good reasons), and it's not even possible on most mobile browsers.
As with the original article I'm talking about desktop apps which would already require an installer. It's just about reducing the pain of that install.
I assume something like QT allows you to script the webview with whatever language you have bindings for? Unfortunately QT+bindings is a pretty long way from 'zero install'