Google acquired it from Upstartle (the company behind the online word processor Writely).

Writely was created in 2005 by Claudia Carpenter, Steve Newman, and Sam Schillace. Google bought Upstartle in 2006 and Writely became the foundation of Google Docs. Google then combined it with other acquisitions, such as 2Web Technologies for spreadsheets, and launched Google Docs & Spreadsheets in October 2006.