Hangouts on Air allowed users to host a multi-user video call while recording and streaming the call on YouTube. Launched September 20, 2011; shut down August 1, 2019 — it lived 7 years. One of 37 Google products killed in 2019. https://arstechnica.com/gadgets/2019/06/google-is-killing-youtubes-hangouts-on-air-this-year/ Data: Killed by Google (killedbygoogle.com, MIT).