Half-Life: Raise the Bar is a fan-made short film inspired by the Half-Life franchise.
RCVR - New Online Sci-Fi Series
RCVR is a new sci-fi series exclusive to Machinima.
Portal 2 - Boots
The science of the boots used in Portal 2 is explained in this latest video from Valve.
Portal 2 - Turret Trailer
Valve spills the beans on the technical aspects of the turrets encountered in Portal 2.