Media Source Extensions™ publication history Date Status 21 September 2022 Working Draft 26 July 2022 Working Draft 19 May 2022 Working Draft 18 May 2022 Working Draft 10 May 2022 Working Draft 5 May 2022 Working Draft 30 March 2022 Working Draft 18 March 2022 Working Draft 17 February 2022 Working Draft 30 September 2021 First Public Working Draft