Gabe Newell and Mike Harrington worked together at Microsoft, gaining experience in software development and management. During their time at Microsoft, they developed a shared vision for the future of gaming.

Newell and Harrington left Microsoft to co-found Valve L.L.C. Their shared vision for the future of gaming and their complementary skills made them a strong team. They invested their Microsoft fortunes into creating Half-Life.

Half-Life's critical acclaim and commercial success solidified Newell and Harrington's partnership. The game's innovative storytelling and engaging gameplay demonstrated their shared vision for the future of gaming.

Mike Harrington leaves Valve in 2000 to spend time with his family. Although the partnership ended, it was on amicable terms.

Despite Harrington's departure from Valve, Newell and Harrington have remained friends. They have spoken positively about each other in interviews, and they have occasionally collaborated on projects outside of Valve.