WebGL hacking on 8.1
One of the good things they added in windows rt 8.1 is WebGL. For a device they essentially neuter from the development side the only open vector for non jailbroke development hacking is ie.
They even have some examples which use the canvas which should run on IE10 (RT 8.0).
Check out their samples page here (they load pretty slowly like 10 secs on surface 1) :
(Might want to start with the buffer geometry / lines one)
For users on 8.1 most work but some may not (maybe gaps in api coverage)... and some require mouse keyboard, but most respond a little to 'poking the screen'. There may also be differences between intel video drivers and NVidia tegra driver support.
If you download from main page http://threejs.org
and extract zip you can run most of those from filesystem (the ones which load assets like models wont work)... and you can load them fullscreen without the menu bar on left.
If your on RT 8.0 scroll down to css3d and canvas sections to try those.
There are a few other (non three.js) demos like the chrome demo here :
And Glacierworks demo :
(then click on Everest in top menu bar)