>>> "What is the most efficient low-level method for data transfer between two processes provided by the operating system?"<p>Unix Domain advantage is that its just another re-direct, another pipe for i/o. IPC involves design-time consideration ;)<p><a href="https://en.wikipedia.org/wiki/Named_pipe#In_Windows" rel="nofollow noreferrer">https://en.wikipedia.org/wiki/Named_pipe#In_Windows</a>