Let's Encrypt began testing their free SSL certificates this week and will formally launch November 16th (two months from now)
https://letsencrypt.org/2015/08/07/updated-lets-encrypt-laun...
However they have no plans for wildcards and you have to renew every 90 days (automation possible).
They also do not have their intermediate certificate working yet (but will have to by November).
But if you do not need wildcards, the StartSSL free certificate has been an option for a long time:
http://www.startssl.com/?app=33
(startssl works in all browsers and has a 1 year renewal)