Gabe Newell and Mike Harrington left Microsoft in the mid 90s after seeing that Doom had a larger install base than Windows did. Newell recalls that the Microsoft sales people were racking their brains trying to figure out how to outsell a DOS based video game. After seeing that potential, Newell felt he could add something to the process.

The first thing that Newell and Harrington did was to secure a license to use the Quake Engine. It was a fairly popular gaming engine that powered the entire Quake series, and many games of the era. They used the physics and tool sets to begin work on their first game, Half Life. The story followed a voice-less protagonist’s journey to solve the fallout of an inter-dimensional rift.

It was released to critical and user acclaim, and followed up by two expansions and a few modifications.

Valve spun that success into a sequel called Half Life 2. This is where Valve ceased to become a mere developer, and began to work on something bigger. The Source engine they created spawned countless mods, and gave birth to new titles in Valve’s franchises.

Steam, Valve’s video game distribution platform, has changed everything about games distribution. The platform offers AAA rated titles at prices that are often pennies on the dollar, with a digital rights management platform that protects content and provides a near-seamless effect for players. Valve’s newest title, DotA 2, is currently responsible for the highest grossing tournaments in eSports history. Valve is estimated to have $2.5 billion in equity, with Newell boasting that his employees provide more productivity per worker than almost any US based corporation in existence.