anchor.diff:      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;
  +    Unix-like environment for Windows (both 32-bit and 64-bit).
     - a native Win64 port (64-bit Windows), built with the Microsoft
       development tools.
   
  
positive.code: 
  |=====
  |           | Native MS       | Native MinGW        | Cygwin
  |64 bits?   | Win32 or Win64  | Win32 or Win64      | Win32 only
  4+^| Third-party software required
  | for base bytecode system              | none          | none          | none
  | for ocamlc -custom                    | MSVC          | Cygwin        | Cygwin
  
negative.code: - 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.
  - 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.
  