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Comment by Tichy | Hacker News Reader

Basically, the jvm.

I have to admit that it took me a little while to figure out exactly how cool the JVM is, and how much of a standalone product it is. Its exciting to see so many languages targeting the JVM and taking advantage of the many years of development and optimization that have gone into the JVM.

What I find kind of funny is that both major JVMs (Sun's and IBM's) were both originally Smalltalk VMs that were basically abused (crippling them with Java's security model among other things in Sun's case, not too sure about IBM) to run Java.

HotSpot is built on top of the Strongtalk VM, which is very interesting in several ways. First, it's a Smalltalk implementation with optional strong static typing. Second, since 2006 it's been available as open source:

http://strongtalk.org/

I believe, along with Common Lisp and its VM, it's the only such option on the market. Clojure may have optional static typing -- which, running on the HotSpot JVM, would mean bringing this "full cycle" -- but I need to RTFM before I say for sure.

Clojure has optional type hints.

Ex: (fn [#^String foo] (.length foo))

See http://clojure.org/java_interop#Java%20Interop-Type%20Hints

Will there be a tail recursion on jvm?

It's possible to tail recursion on the JVM, especially with a statically typed language (see Scala for a classical approach, see Clojure's loop/recur for a slightly different approach). Not tail call elimination and mutual recursion, however. That is, however, if you want the compiler to output code that's fully backwards compatible with Java (which is what Scala and Clojure do).

late hit:

I've seen chatter that scala has TCO, clojure doesn't (kinda like, what's wrong with clojre?). Read what Rich hickey has to say

http://groups.google.com/group/clojure/msg/946d98e5b88a6497

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