Valve show a grittier more realistic use for Source Filmmaker with a trailer for Counter-Strike: Global Offensive.
Valve have announced they will release their Source 2 engine for free to content developers.
Half-Life Black Mesa
A relentless team of fans have finally released Black Mesa a remake/upgrade of the first Half-Life game from Valve.
Portal 2 - Boots
The science of the boots used in Portal 2 is explained in this latest video from Valve.