[Apocryphon]

HTML5+js is very locked down?

[nerdponx]

Maybe in the sense that webpages cannot talk to each other directly.

[gameswithgo]

or the hardware

[pjmlp]

Yes, think of ChromeOS.

You are locked to the browser sandbox and web sites, which you will never see the code running on their servers.

X11 terminals are back, just prettier.