I saw on the twitters today that the classic blog post where David Nolen introduced Om is two years old today. Even though I’ve never written a single line of Om or ClojureScript, this post (and Om itself) was extremely enlightening for me. Furthermore I think it’s had a profound effect on the JavaScript ecosystem at large.
React
It’s hard to imagine now, but the frontend community’s initial response to React was pretty lukewarm (at least from where I was sitting). David’s post made a lot of people sit up and take notice. I don’t think it’s coincidence that interest in React began to really take off shortly thereafter. React’s benefits are pretty well documented by now, but its widespread adoption was never a given.
Immutable Data
While certainly not a new idea, immutable data structures only seemed to "catch on" in the front-end world since Om’s release. Now popular libraries like Immutable.js give them a more familiar JavaScript API, and they’re even being proposed for inclusion in a future version of EcmaScript.
Single State Atom
Another technique popularized by Om is placing all application state in a single object. Easy undo/redo and backup/restore are its most commonly cited benefits, but I'm curious to see what else it makes possible as more people explore this idea. Omniscient and Redux (among others) have brought it to JavaScript, and the latter is currently seeing an explosion in popularity.
Diversity in Frontend Architecture
In late 2013 it seemed like most people were pretty happy writing MVC*-ish* apps in JavaScript. The Om blog post was one of the first pieces I saw that not only gave a cogent argument against it, but also presented a reasonable alternative. A few months later, Flux was released. The breaking of the MVC monoculture has allowed a lot of diverse ideas to flourish, which has been both fascinating and illuminating. Let’s hope it continues for a while yet.