How is C++ on Unix different from C++ on

[Kavitha J]

Windows? The only difference I have encountered is fork/exec calls that is there in Unix. Is there any other difference?

[dvari]

The language itself is not different.

Writing applications for the OSes is different because of things like how the underlying OS manages resources such as processes, threads, semaphores, mutexes, pipes, etc. Unix (and Linux) generally use Posix, while Windows is its own animal.