We are the windows package maintainers of PostGIS. We build these packages using MingW chain of tools. For other packages we fancy that do not come packaged with the windows VC++ builds, we also build these under mingw. We've described some of these already in File FDW family. For windows 32 builds we build
with the commonly known MSys/Mingw32 chain (but an older version 1.0.11)
because of issues we have building with the newer msys/mingw 32.
For windows 64-bit installs, we build with the mingw-w64 chain and in fact
we like the ming-w64 chain so much that we plan to migrate our Mingw32 to mingw64. We have PostgreSQL 9.2 and PostgreSQL 9.3 successfully installing under the mingw-w64 for windows 32 just fine (older PostgreSQL we experience a winsock.h something or other error which we are working on troubleshooting. For 64-bit we use ming-w64 for building extensions for PostgreSQL 9.0-9.2 and soon 9.3 with some minor issues. Some people have asked us, why put yourself thru this torture? Why not just build on MS VC++ for everything? Originally we had started on mingw because PostGIS needed a Unix like environment to compile and run thru the battery of tests. This is still the case, though PostGIS is planning a CMake move with help from Mateusz Lostkot which hopefuly will provide a better cross-platform experience and allows us to integrate pgRouting (which already is on CMake). Paul Ramsey rewrote many of the regression test scripts to be completely Perl based and not require sh. The other reality is we just prefer mingw and can't really stomach having to work with VC++. I'll describe why and why not build with mingw and deploy on VC++ compiled PostgreSQL.