There's Beam [0], it's quite new but I've been quite amazed by their work. They invented some sort of own protocol built on web standards [1]. Also, their streams are actually live (i.e. minimal delay), it's all HTTPS and a lot of their work is open source. [2]
Thanks for the link. Looks neat, but sadly doesn't seem to be working in Firefox for Linux. Don't have time to dig into why right now (missing MSE? some codec I don't have?)