See http://www.mingw.org.

Gloss mingwin as "Minimalist [GNU]
for Windows" [http://www.mingw.org/].
Is "[mingw32]" an exact synonym?  In any
case, one often sees the latter, also.
Some idiolects seem to favor "minimal"
for "minimalist", also.

Most of the excitement linking mingwin
and [Tcl] has to do with [critcl] and
its potential, first to maintain portable
extensions far more conveniently, and 
then to ...
In this scheme, mingwin provides cross-generation and cross-linking 
(among other) capabilities.


[DRH] offers the application note, "Cross-Compiling Tcl/Tk 8.3.2 for WinNT
Using Mingw" 
[http://www.hwaci.com/sw/mktclapp/win32-compile.html].

[SLB]: The download page of the mingw site offers a bewildering (to me) array
of packages. The two important ones are:

   * msys (which gives you the shell)
   * mingw (which gives you the C compiler)

The gcc package also contains a compiler but without the assembler and doesn't
seem to be needed.

As far as I know, configure does not support compilation with Visual C++.

When starting the shell (C:\msys\1.0\bin\sh.exe) give the switch --login,
so $PATH is correctly setup.