Regarding pipes and pipe-like interprocess communications facilities in other operating systems, VMS has always had a pipe-like communications pseudo-devices called mailboxes.  The main difference between Unix pipes and VMS mailboxes is that pipes have distinct read-only and write-only file descriptors.  Mailboxes do not--channels (VMS-speak for file descriptors) assigned to a mailbox can be used for both reading and writing.  This means that it is not possible to do "broken pipe"-type detection on a mailbox.  This very much restricts the usefulness of mailboxes.

I wrote a true pipe device driver for VMS as part of the DEC Shell product (a port of the Unix Bourne shell to VMS).

-Paul W.