Portal 2 is a puzzle game developed and published by Valve Corporation.

Steam is a program made by the Valve Corporation that sells video games which can be downloaded to a computer.

Valve Corporation is planning to also have their system, the Steambox, come out by the end of 2013.

Source is a 3D video game engine developed by Valve Corporation.

Valve Corporation was long known for an exceptionally protracted development schedule.

Since Valve Corporation's debut, it has expanded both in scope and commercial value.

Varoufakis has since left his position at Valve Corporation.

He now works in the videogame industry where he's a full-time writer at Valve Corporation.

It was developed by Valve Corporation and released on June 1, 2006.

Portal is a series of puzzle-platformer video games developed by Valve Corporation.