Haxe vs OCaml

Haxe allows you to develop for Web, iOS, Android, Blackberry, Windows, OSX, Linux and others, all at once, without the need to switch languages and maintain separate code bases.

This is possible because Haxe can compile to JavaScript, ActionScript, Flash AVM bytecode, C++, Neko, PHP, C# (.NET) and Java.

Support for even more platforms and languages is under development.

The language was designed to be very expressive with the smallest possible amount of syntactic sugar. There are actually fewer keywords than other languages with similar power.

Haxe can easily compile over 100,000 lines of code to JS in seconds on a mid-spec computer.

The language is very easy to learn for those with background in JavaScript or ActionScript 3.

Haxelib (common library repo) and other sources contain large codebases for anything from cryptography to communications. A lot of these are fully cross platform and work with the JavaScript target.

The JavaScript target can be used for everything from node.js server applications (with code completion) to games using either the Flash-like OpenFL library or direct canvas or WebGL programming.

Haxe has been around for more than 10 years (since 2005) and whilst not the most popular project, has had continuous growth.

Highly unlikely to disappear or for support to stop.

Friendly community

One big advantage over pure javascript, (or some other languages listed here) is that Haxe will pick up a whole range of errors when you compile, saving you the pain of having to try and debug them later. This includes everything from syntax errors ("Unexpected ;") to type errors ("Class user has no field username. Suggestion: username").

Code completion is built into the compiler and available to the IDE allowing for much smarter code completion that can actually parse and understand the syntax tree.

The output that is generated can be trimmed using "dead code elimination" to only include those functions and libraries that are strictly necessary. All code is very readable with only minimal extras for specific functionality.

Small output is good for frontend development as file size is a major concern.

After a type is inferred from its context, it cannot be changed to a new type, and type safety is done at compile time so it stays safe without the extra maintenance required for static typing.

Syntactic macros allow you to extend compiler features at the syntax tree step. Macros come into play after code is parsed into the abstract syntax tree, and macros allow you to transform it before the rest of the compilation completes.

This provides for immense power, while at the same time scoping the extensibility at a level that is powerful, but well constrained.

You can use the same classes on the server as you do on the client where applicable. This saves a lot of time.

Haxe has the ability to use "externs". These are haxe files which describe the usage of existing JS libraries. Get code completion and compile-time-checking for everything from jQuery to Node.js.

Even without externs, native JS code can still be used through untyped code.

Haxe has the power and expression to not need the npm dependancy hell that is common in js and typescript, bit it's still simple.

Using a remoting proxy you can get type safe server to client communications, allowing for remote method execution on the server as if they were part of the client side code.

Package tree is just directory tree, it's wonderful!

Haxe supports conditional compilation, so depending on compiler flags Haxe will include or exlcude sections of your code. Making it easy to have debug and release builds.

You can define constants in an abstract enum and when used in a switch/case statement Haxe checks for exhaustiveness, making sure every constant is covered - with no runtime implication.

Haxe compiler will check types when using externs for existing libraries.

You should use externs when calling non Haxe code, but if you just need to call one or two external JS functions, you can skip type checking by calling untyped code.

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.