I can not comment on Niall's post, I'm new here and all these are beyond me.
I managed to fully compile it it under Windows, something compliant with GPL, if anyone is interested read below.
My "porting" is via Cygwin, meaning that you will need both Cygwin's library (libraries ? not sure) and most probably all the standard shell tools, like bash, sed, awk etc that come with , plus the directory tree under c:\cygwin. The developers of astrometry.net warn for the need for shell tools, but I'm not sure if they mean during compilation or during operation of the program. For the same reasons I do not know if a binary distribution has any meaning - without Cygwin it may be unusable. But I may be wrong here , I have years to follow these things. And in any case all these are GPLed, meaning that they can not be included as part of a commercial product, only under the conditions GPL allows. Compiling with the minGW32 compiler may minimize the dependencies on Cygwin libraries, but again I think you will need bash etc., so......
Nevertheless it is fairly easy to have a Cygwin installation just for this. And that means that Georg's script needs the minimum of trimming, basically run the solver via a batch file that will run the program via Cygwin's bash first, or maybe just a "bash -c ...... "will do the trick.
Anyway, for those that are interested to compile it for their usage under Cygwin :
1) Download the setup from Cygwin project and start the installation - follow the instructions
2) During the setup, at the package selection be sure that you included the following:
gcc, sed, gawk, make, automake, pkg-config, python, gzip, bzip2 and all packages related to
cairo, netpbm, libpng, libjpeg, and numpy (libraries etc)
I may miss some packages from the above list, since I had the installation already from the past and some packages have been there for years. You have to play it as it goes, and go back to the setup program later to install any missing package(s). WARNING do not trash the setup program after installation exactly for this reason.
The file README in the archive actually have most of the following steps. The command
is your friend inside a Cygwin bash shell to help you understand how the different Windows drive letters map to Cygwin's unix-like filesystem.
You will need to remember your command line skills, and at least know how to issue commands like cd or ls.
3) open a Cygwin bash shell and untar the package ie, (assuming that you are in the directory that the astrometry.net's source archive is), run
tar xjvf astrometry*tar*bz2
4) edit the file util/makefile.netpbm (use either wordpad or an editor from inside the cygwin shell, eg vim or nano or mcedit) and change line 17 to be
NETPBM_INC := -I /usr/include/netpbm
4) from the top directory run
5) edit your Cygwin $HOME/.profile to add astrometry installation directory in your path.
6) Open a new bash shell, you should have a command solve-field.exe in your $PATH
A word about performance: it is slow comparing to native ports eg under Linux. The following image was solved in about 12 minutes under my Linux box and needed about 30 minutes under Cygwin