This is the official home of Valve.

It might seem strange to add Wikipedia to this directory but it contain some very useful information for Valve’s fans. The sections on the games are very detailed. It is also available in many langauges.

World Of Moo is a blog with a small group of writers. They blog about many aspects of gaming.

Zombie Panic: Source is a survival horror MP HL2 modification. Play as either the survivors or the undead, trying to wipe each other out or completing objectives to escape the horror.