- WebAssembly. It's basically assembly language. But I expect more languages will be created based on it. For example there was ThinScript that compiles to both JavaScript and C. There can be more when people see the chance.
- Reason. I saw Jorden Walke demonstrating ReasonML these days. This guy is the author of React but seems not very active in the past years. I only got to recognize his story in the past weeks(well I'm in Shanghai). I guess Reason will be big news for React community when it's all ready.
- ClojureScript, which is my personal favorite. The thing is I saw David's talk on Reactive Conf and seems ClojureScript will have ES6 module support in the near future, which means it can be integrated into the npm ecosystem. It's late, I already have looked forward to it for so long. It's not new language for the English community, but for China, it's new.
They are mostly for the front-end community.