You are Alfred(Phrédo)Robrtson, an elictrical engineer who helped to construct the Aperture power-grid as well as wire GLaDOS into it. Kept on-site in case of emergency you were forgotten by the now deceased employees as well as GLaDOS*. You are woken up by your containment unit in its final moments of back-up battery life and you alone explore and escape while finding clues piece by piece about the past and present of Aperture Science. You are the Escapist.
A test of the refractive cracked glass textures. Unlike Portal 2 these are textures(Portal 2 uses models) which means that they can be shifted and scaled and in one case repeated for larger surfaces. Useful applications include small or large cracked items with the same refraction, enormous cracked surfaces, and cracks coming from the edge or corner of a glass pane. It also loads faster in-game. Downsides include significantly less quality (due entirely to the engine, the displacement maps are high-res) and that objects held before it will blend with the refraction shaders(hard to notice in most cases)