Like, when you build an API, (or other backend stuff) you're not concerned about browsers or the DOM - thats really just a delivery mechanism. So you can run --harmony within your own server and have it spit out JSON. Client doesn't know or care what your running, just the JSON.
Ah, you mean "server side". Gotcha. Yes, building for the server is easier because you have a single runtime to target. In the case of Node, it's V8. In the case of Dart, it's Dart VM on the server.
