Sturla Molden schrieb:
To my astonishment, I just found out this:
The Windows-port of tcsh has an implementation of fork on top of the Windows API, and the license is BSD (unlike Cygwin's GPL'd fork).
The code implements fork() on top of the NT API, not the Win32 API. The NT Kernel supports all necessary bits and pieces for fork(). However the features aren't exposed in the Win32 API layer. According to several internet sites only the POSIX layer for NT exposes fork().
fork() is an efficient and fast op on Unix systems like Linux and BSD, because it uses a technique called copy on write (cow). I couldn't find any information if NT uses cow, too.