It seems like the scene might have been built with Unity and was then exported.
There is a data file loaded[1] which states its generator is "ThreeExporter.cs" in version 4.0.
[1] http://hellorun.helloenjoy.com/assets/station/station.js
Re:HelloRun - A WebGL 3D Game
by braco_alva on Tuesday September 03, 2013 @11:19PM
(#6325339)
AFAIK it only does NaCl besides their Web Player.
does unity now target html5 without any depending on a webplayer plugin?