React, Flux, GraphQL, Hack, HHVM...? All of this and more!
However it seems that the trends are showing more general interest in TypeScript, as the project reaches it's all time peak search interest in July 2017, almost five years after it's initial release in October 2012:
As TypeScript continues to add features, with a steady pace, with TypeScript 2.4 bringing support for Dynamic Imports and more, it looks feasible that TypeScript adoption will continue on this upward trend. TypeScript is definitely a language to consider when writing Node.js or Browser applications.
More about TypeScript: