Hey Benoît,
yes there are more than one cnc manufacturers in Europe, and spindles as well 
I understand you totally with this. I use Windoze only in virtual machines when I need the full capability of proprietary drivers for some printers and scanners.
On the cnc machine’s page mentioned above if you search for ‘linux’ you find Linux CNC. LinuxCNC is very capable. And it runs on so many hardwares, you can choose from so much. Mesa even has a card for Raspberry Pies. And that wouldn’t even be necessary with its 26 GPIOs. The controller of the machine above connects with parallel port, so no problem for any PC with linuxcnc (and a parallel card like the ones from Mesa).
Tags: “Raspberry Linuxcnc”, LinuxCNC home, LinuxCNC - Wikipedia