Harrington was a programmer at the video game developer Dynamix and a designer on the Windows NT operating system at Microsoft.

[4] Harrington sold his Microsoft shares to fund his half of the startup.

[5] His wife at the time, Monica Harrington, was Valve's marketing strategist in its early years.

"[7] On January 15, 2000, Harrington sold his stake in Valve to Newell and left to spend time with his wife.

[7] In 2006, Harrington co-founded the photo editing service Picnik with friend and former colleague Darrin Massena.