anchor.diff:  - There is a problem with cygwin's port of gcc version 4.5.3.  You should
     use cygwin's setup program to downgrade to 4.3.4 before compiling OCaml.
   - The replay debugger is fully supported.
  -- When upgrading from 3.12.0 to 3.12.1, you will need to remove
  -  '/usr/local/bin/ocamlmktop.exe' before typing `make install`.
   - In order to use the "graph" library, you will need to use Cygwin's
     setup.exe to install the xinit, and libX11-devel packages before compiling
     OCaml.
  
positive.code:     compiler from the mingw-w64 project, packaged in Cygwin
      (under the name mingw64-x86_64);
    - a port consisting of the Unix sources compiled under the Cygwin
      Unix-like environment for Windows;
    - a native Win64 port (64-bit Windows), built with the Microsoft
      development tools.
  
  
negative.code: 
  |=====
  |           | Native MS       | Native MinGW        | Cygwin
  |64 bits?   | Win32 or Win64  | Win32 or Win64      | Win32 or Win64
  4+^| Third-party software required
  | for base bytecode system              | none          | none          | none
  | for ocamlc -custom                    | MSVC          | Cygwin        | Cygwin
  