Last week some nice folks assured me tooling was good in Clojure; and not a total time suck, and so I'm getting ready to take the jump I think... but, one thing I'm still really skeptical about... is embodied in this paragraph:

> The way the languages are integrated today, Clojure developers doing full-stack development don’t really have to think about data serialisation/deserialisation. Writing code for frontend and backend differ mostly just in the way that the different implementations access the host platform. The functional aspects of Clojure, especially the immutability and focus on referential transparency, ensure that source code is mostly split into chunks of highly portable code, with the host-interop conveniently put aside in its own sections. You can move code between frontend and backend at your leisure.

Is it really that good using Clojure across environments and runtimes?

I ask because I tried all of this with Scala years ago (I loved the language) and Ruby to an extent, but it was pretty miserable or rather there was really no reward but more effort on my part. I.e. I'd spend more time annotating, bridging, and learning how to interact with the different runtime than I would writing actual feature code[1].

Or like what are the killer libraries everyone loves? Do they (libs/frameworks) support different clojure runtimes ("hosts?") outta the box? Is it easy to write "pure clojure" projects that work for any clojure project?

The one I know about or have heard most about was Datatomic, which always sounded freakin' brilliant, but I don't fucks with non-free databases. Arcadia I just saw and it looks cool but, it also seems like a dumb mountain to climb, if that's how I wanted to start screwing around with Clojure.

[1] Tools like Scala/ScalaJS and RubyMotion (back in the day, heh), were the reasons I ended up a polyglot. They're great tools, if you know the platform, if you don't, you're pretty much still fucked... but once you know the platform it's kind of hard to want to use them.