I just found OCaml are under GPL with a special exception
"As a special exception to the GNU Library General Public License, you may link, statically or dynamically, a "work that uses the Library" with a publicly distributed version of the Library to produce an executable file containing portions of the Library, and distribute that executable file under terms of your choice, without any of the additional requirements listed in clause 6 of the GNU Library General Public License. By "a publicly distributed version of the Library", we mean either the unmodified Library as distributed by Inria, or a modified version of the Library that is distributed under the conditions defined in clause 2 of the GNU Library General Public License. This exception does not however invalidate any other reasons why the executable file might be covered by the GNU Library General Public License."
Does it mean it's totally OK to code with it and distribute/sell it without the disclose of my code as long as I don't modify OCaml's components?