Is it worthwhile to explore Clojure for web-dev seriously or more as a toy?
The deployment is the very well understood JVM and standard web servers. There's a common HTTP middleware framework (Ring), lots of choices for HTML generation and ClojureScript allows some code-sharing with your client side (compiles to JS).
On the back-end, you could use any Java library. On the front-end, you could use any JS framework (e.g. see https://github.com/omcljs/om)
It featured (to the best of my memory):
A new data model for om next. Instead of cursors, components have a composable datomic style DSL to locate their data, which is pluggable and can be from local memory or a cached server side query.
Using this approach you can request data in new ways from the client without adding server side code.
An update on cljs in cljs (small example but showing lots of plumbing work done)
The path to react native, repls and dynamic code loading on the device (was demoed) via ambly
Check out this:
https://github.com/bhauman/flappy-bird-demo
It uses figwheel for the dynamic changes of state when you change to code, and it renders it without reload ala Bret Victor style. The first time I saw it I was amazed. It speeds up prototyping so much.
The out of the box performance is decent as well, Ring and Hiccup is pretty lean but you can go for more heavy frameworks (I don't have any experience with those).
I personally use Reagent + Ring, found it easy to use and get productive in a day.
If you haven't used LISP or any homoiconic language before it might look little weird at first but I found it easy to explain to people.
About the toy part, what is your definition of toy?
git clone blah && cd blah && brew install leiningen && lein figwheel
I don't know what is you operating system and other details.
You need leiningen, that is the make of Clojure, the repository cloned and you are good.
https://github.com/technomancy/leiningen
Clone the repo, `lein figwheel`, http://localhost:3449/index.html
1. Clojure's tools for making abstractions are orders of magnitude better than Java's, so our codebase is significantly smaller and simpler than what it'd look like in Java.
2. Clojure lends itself very well to a REPL-oriented kind of iterative development that speeds up writing and testing code tremendously, compared to the typical Java workflow.
At its core, Clojure is basically just data and functions. Once the switch flipped in my mind, I found that to be simpler and more straight forward than any of the languages I worked with before.
When the majority of your code is side-effect-free, pure functions (and Clojure makes it very easy to structure your code this way), it becomes very easy to reason about. And very easy to test, with minimal ceremony!
P.S. When I was learning Clojure, I kinda devoured all the resources I could find. A couple interesting looks at the language from the perspective of Rubyists:
http://briancarper.net/blog/536/clojure-from-a-ruby-perspect...
http://confreaks.tv/videos/rubyconf2009-clojure-for-ruby-pro...