Dear Gabriel, To solve that problem we need a better testing infrastructure for ocamlbuild, but also get more tests from Windows users to provide feedback on other approaches or patches reworks, etc. If someone, for example you, is willing to start a more persistent approach of iterative improvements and tests, I think that things could improve rather quickly. well I am using ocamlbuild daily on Windows, currently with MinGW cross OCaml on cygwin, but I would like to switch to a native MinGW solution. I cannot make any long term promises, but at least for a midterm transitional period (say 6 months), I have no issue to run a test suite every week on plain Windows, on plain Cygwin, on MinGW cross on Cygwin and also on Linux. Also I have scripts which fully automate setup and test of plain MinGW, MinGW cross on Cygwin and plain Cygwin OCaml. That is you start a batch file, and it will install a fresh cygwin and start a bash script which downloads and compiles the respective flavor of OCaml and run some tests with 0 user interaction. If this helps, I would be happy to tailor these scripts to whatever automation systems you have and contribute them. Privately I am using Amazon AWS (that is rental of datacenter infrastructure of Amazon’s own datacenters) quite a bit. If the OCamlbuild community has issues with setting up a reliable multi-platform server infrastructure, this might be an effective and very low cost solution. You get virtual Windows and Linux servers with root access and customizable specs (memory, CPU). The good thing is that you pay for the servers only when they run. I think you would have to test quite a lot to get a bill of more than 5$ a month, likely it will be around 1$. If this is something we want to look into, I would pay the bill privately for 2 years (up to 100€). One can integrate such systems easily with other systems, e.g. you do some signed http post with a script, which triggers a process on an Amazon lambda server, which boots up the real servers which then runs the tests, post the results on some web storage and shut down again. I really love this stuff ;-) An interesting question is how many “obscure” test cases for ocamlbuild we can get. My own projects use Menhir, Ocamllex and a few non-standard libraries, so at least this would run. Best regards, Michael Intel Deutschland GmbH Registered Address: Am Campeon 10-12, 85579 Neubiberg, Germany Tel: +49 89 99 8853-0, www.intel.de Managing Directors: Christin Eisenschmid, Christian Lamprechter Chairperson of the Supervisory Board: Nicole Lau Registered Office: Munich Commercial Register: Amtsgericht Muenchen HRB 186928