I gave a short talk about the state of JavaScript implementations this year at the Web Engines Hackfest.
The talk goes over a bit of the history of JS implementations, with a focus on performance and architecture. It then moves on to talk about what happened in 2014 and some ideas about where 2015 might be going. Have a look if that's a thing you are in to. Thanks to Adobe, Collabora, and Igalia for sponsoring the event.