Clojure vs OCaml

Clojure programmers are highly encouraged to use immutable data in their code. Therefore, most data will be immutable by default.
State change is handled by functions (for transformations) and atoms (an abstraction that encapsulates the idea of some entity having an identity).

Being a LISP, programs are simple: they're just functions and data. That it doesn't get bogged down with syntax or the loftier FP concepts like monads makes it one of most approachable functional languages for beginners.

Simplicity is one of the pillars on which Clojure is built. Clojure tries to solve many problems in software development as simply as possible. Instead of building complex interfaces, objects or factories, it uses immutability and simple data structures.

Since Clojure is designed for concurrency, it offers things like Software Transaction Memory, functional programming without side-effects and immutable data structures right out of the box. This means that the development team can focus their energies on developing features instead of concurrency details.

There's a very large ecosystem of high-quality Clojure libraries which developers can use. One example is Incanter. It's a great data analytics library and a very powerful tool for dealing with matrices, datasets and csv files.

Clojure compiles to JVM bytecode and runs inside the JVM. This means that applications written in Clojure are cross-platform out of the box.

The creator is so awesome, he's a feature. Just look up his talks and see why.

A superb data processing language. While rich type and specification systems are available they are optional.

Clojure has an elegant macro system which enables language additions, Domain-specific languages (DSLs), to be created much easier than most other languages (with the exception of Racket, perhaps).

Leiningen is a very useful tool for Clojure developers. It helps wiht automation, configuration and dependency management. It's basically a must for every Clojure project.

Refreshing, BTW!

Nightmod is a tool used to make "live-moddable" games. It displays the game's code while you are playing and allows you to inject new code using Clojure. This can be a fun and useful experience for people trying to learn Clojure.

Functional programming is based on the lambda calculus. OCaml is in its functional parts almost pure lambda calculus, in a very practical manner: useful for many daily programming tasks. The acitve development makes improvements to the type system like generalized algebraic data types (GADT) or polymorphic variants, so when learning this language you get at once a down to earth usable compiler and advanced abstraction features.

It steers you towards a functional style, but doesn't bother you with purity and "monads everywhere" like other languages, such as Haskell.

Strong focus on *nix systems, lacking native support for MS Windows
Lacks native support for Windows systems.

OPAM is a package manager for OCaml, which is really easy to use, just like npm. It creates a .opam folder in home directory.

The documentation is great as well, and you can switch between multiple versions of OCaml for each project. You can also package your project and publish it on OPAM repositories, even if the dependencies do not exists on OPAM.

OCaml is compiled to native binary, so it's amazingly fast. Being a member of ML-family languages, it has expressive syntax for trees, and has great LLVM support.

The syntax is consistent, some syntaxic sugar but at a reasonable level, so reading code of others isn't too much confusing.

The merlin editor tool provides all you need to develop OCaml in your favourite editor.