That's odd given how easy it is to shim the Linux/POSIX socket API - most of it anyway - on Windows. I made good money back in the day by writing server software that had to compile and run on both Windows and Linux (actually it was never deployed on Windows, but on an embedded Win32 compatible OS, but they were planning to move to Linux, so I did all development on Windows, tested on whatever embedded platform they used and Linux) - the "compatibility" layer was a few dozens of lines in a header file.