2007
- May 17: OTW idea first proposed
- May 20: First call for volunteers
- August: First donations received
- December 11: OTW website goes live
- Legal Advocacy launched (first OTW project)
2008
- February 1: First TWC call for papers
- March 1-18: First OTW fundraiser
- March 25: First code for AO3 completed
- June 3: Fanlore launched
- August 4: First fandom page on Fanlore created (Die Hard)
- September 15: First TWC issue published
- October 3: AO3 launch announced
2009
- February 16: Vidding History Project launched
- June 18: Fan Culture Preservation Project launched
- July 13: GeoCities Rescue Project launched
- October: First board election
- November 13: AO3 enters open beta
2010
- January: AO3 reaches 5,000 canonical fandoms
- June 6: Symposium blog launched
- October 10: AO3 reaches 10,000 registered users
- TWC reaches 100 published items
2011
- May 16: Open Doors site launched
- October 12: AO3 site design revamped
2012
- February 26: Open Doors begins importing archives to AO3
- September: AO3 reaches 10,000 canonical fandoms
- TWC releases fifth anniversary issue, reaches 200 published items
2013
- March: Symposium blog becomes Fanhackers
- June 18: Fanlore reaches 25,000 articles
- December: 5th Open Doors import to AO3 completed
2014
- February 15: 500,000th edit to Fanlore; AO3 reaches one million fanworks
- February: The Fan Fiction Studies Reader published by TWC editors (first OTW-supported book)
- June 8: Fanlore reaches 30,000 articles
2015
- February 15: First International Fanworks Day observed
- March 20: AO3 servers moved to OTW-owned rack
- December 20: AO3 reaches two million fanworks
- December: AO3 reaches 20,000 canonical fandoms
2016
- Fanlore reaches 40,000 articles
- August: 20th Open Doors import to AO3 completed
- October 31: AO3 reaches one million registered users
2017
- April 28: AO3 reaches three million fanworks
- June 26: AO3 reaches 25,000 canonical fandoms
- September: TWC publishes 25th issue