Wasn't last night, but fairy recent. The world was a physical representation of the internet, and you could transfer between areas instantly with each site being a different area. Some time before the dream, there was some sort of monumental war that 4chan and Tumblr joined forces in, and lost. The joint realm between the two was in ruins, and it was this massive, derelict industrial factory type place with massive steel tubes. Or something. I had been hearing things about the old war throughout a chunk of the dream, and eventually stumbled upon the outskirts of the industrial ruins by accident. I almost considered venturing in, but then I saw Gabe Newell and all nine classes of Team Fortress 2 playing basketball on a nearby court. I almost joined them, but quickly backed off thinking "No, they're beta testing for future updates, leave them be."