Clojure

http://clojure.org/rationale
Core data structures mutable, not extensible
Not in R^₆RS and Racket.
Lambda calculus yields an extremely small core
Lisp is not based on lambda calculus.
[Clojure] Extends the code-as-data paradigm to maps and vectors
"Look at me, hashes and vectors can be used where you usually put just functions! How cool I am? Everything is an Object! A Java object!"
Defaults to immutability
So does R6RS
But if a data structure can be mutated, dangerous to presume it won't be
Not if you're not a idiotic fucktard who doesn't know what functions destructively modify your data structure and what don't.
In CL, it's usually remove-* for pure functions and delete-* for destructive ones.
In Scheme, it's a ! at the end of the function name.
Clojure is a functional language with a dynamic emphasis
All data structures immutable & persistent, supporting recursion
Heterogeneous collections, return types
Dynamic polymorphism
Purely functional buzzword monadic zygohistomorphic compliance: ACHIEVED
VMs, not OSes, are the platforms of the future
Clojure's inventor is a fucking faggot.
Bytecode + JIT compilation
Abstracts away hardware
Too bad with JVM you need to compile first to your Holy Panacea Bytecode, abstracting the hardware with more (but abstract!) hardware.
New way (JVM, .Net)
Common runtime independent of language
Fuck Lisp purity and Satori, JAVA ALL THE WAY DOWN!
C linkage insufficient these days
This made me laugh.
Write Java in Java, consume and extend Java from Clojure.
Like I just said:
Fuck Lisp purity and Satori, JAVA ALL THE WAY DOWN!


Conclusion:
TOO BAD CLOJURE FUCKING SUCKS AT LISP

Clojure's inventor is a fucking faggot.
Can't be more of a faggot than Slava Pestov. And I bet Clojure is more useful than Factor just by being able to harvest all those Java libraries.

Don't really know why Factor came to mind when I read OP's post. Hmm.