Lil Guardian Pyro is the winner for the best overall prize at this year's Valve Saxxy annual animated film competition.
When Gordon Met Chell
Portal joins forces with Half-Life in this short film called When Gordon Met Chell.
The first minutes of the original Half-Life are brought to life in this live action short, Half-Life: Origins.
Portal 2 - Boots
The science of the boots used in Portal 2 is explained in this latest video from Valve.