Gabe Newell ordered to make in-person deposition for Valve v. Wolfire Games lawsuit
(www.gamesindustry.biz)
https://en.m.wikipedia.org/wiki/Direct2Drive
Steam didn't allow 3rd party titles until late 2005 but Direct2Drive launched early 2004.
Stardock Central was 2001.
https://en.m.wikipedia.org/wiki/Stardock_Central