Half-Life: Raise the Bar is a fan-made short film inspired by the Half-Life franchise.
Protector is an animated short created in Source Filmmaker about the harsh realities of civil protection in Half-Life's City 17.
Meet the Medic - Behind the Scenes
See outtakes and learn about Valve's creative process in this behind the scenes article for their Meet the Medic short.
Portal 2 - Boots
The science of the boots used in Portal 2 is explained in this latest video from Valve.