Another difference I feel is worth mentioning: events in Cycle.js are "pull"-based. Look at how you can select an element in Cycle's DOM tree and subscribe to e

Another difference I feel is worth mentioning: events in Cycle.js are "pull"-based. Look at how you can select an element in Cycle's DOM tree and subscribe to events to it as a stream. Events in re-frame (and reagent and React.js in general) are "push"-based. You must be explicit in your UI tree which events we care about and when they are emitted. I actually wrote a library a long time ago[0] to invert this in React and expose a more pull-based event API, but in practice it wasn't very ergonomic. [0] https://github.com/Lokeh/observe-component https://github.com/Lokeh/observe-component