The way we export the module is changed. For legacy reasons we also supported .EventEmitter property on the returned eventemitter3 object but this has been completely removed. So your previous:
var EventEmitter = require('eventemitter3').EventEmitter;Should be changed to:
var EventEmitter = require('eventemitter3');In addition to that we've made a breaking change the internal argument order of the removeListener api. Historically we used the third argument as indication that only once listeners but we've changed to allow the third argument to be used as context argument as we could also remove listeners based on the context.
Other than that, we added support for a second argument in the listeners API. Happy hacking.