[tel]

OCaml is strict and impure, Haskell lazy and pure. Syntactically they're pretty different, but since they both make heavy use of the H-M type system you see pretty similar semantic operations across the board. Probably the first thing that sets them apart is that IO is a lot more direct in OCaml, a direct implication of strictness and impurity.

Extensions to the type system are really different, OCaml's is more flexible and specific, but Haskell's is very convenient, but by the time that becomes an issue you'll probably know a lot more of how the languages differ.

[eru]

> Syntactically they're pretty different,

Did you want to say that they are pretty similar? Or semantically different?

[tel]

Syntax is different, semantics are informed by the type system so programming in one after being familiar with the other is pretty concept-friendly.