eventemitter3
EventEmitter3 focuses on performance while maintaining a Node.js AND browser compatible interface.
eventemitter2
A feature-rich Node.js event emitter implementation with namespaces, wildcards, TTL, async listeners and browser/worker support.
pubsub-js
Dependency free publish/subscribe library
nanoevents
Simple and tiny (107 bytes) event emitter library
centrifuge
JavaScript client SDK for bidirectional communication with Centrifugo and Centrifuge-based server from browser, NodeJS and React Native