Not sure about revocation. Sponsorship is provided by multiple companies, including Mozilla. See https://letsencrypt.org/sponsors/ https://letsencrypt.org/spon

Not sure about revocation. Sponsorship is provided by multiple companies, including Mozilla. See https://letsencrypt.org/sponsors/ https://letsencrypt.org/sponsors/ and https://letsencrypt.org/2015/04/09/isrg-lf-collaboration.html https://letsencrypt.org/2015/04/09/isrg-lf-collaboration.htm... for more.