Lors de votre prochian redémarrage de Steam, celui-ci corrigera/ajoutera au source Engine :

• Added XSI addon for importing and exporting SMDs
• Added simple SDK bot sample code for adding bots to your mod
• Added source files for six Half-Life 2 single player maps
• Added interface plugin to add bots to mods
• Fixed resource leak in the SDK launcher and vconfig utiity
• Added bspzip tool -- allows you to compile custom content directly into a .bsp