-*- mode: outline; coding: utf-8 -*-

* MS Windows.

* X Windows.

X11 selection transfers (which both PRIMARY and CLIPBOARD are instances of)
are done through synthesized X11 events and properties changes.

The messages used to transfer the selections have a maximum size that's
actually quite low (a few kilobytes).

See

  http://standards.freedesktop.org/clipboards-spec/clipboards-latest.txt
  http://www.jwz.org/doc/x-cut-and-paste.html
  http://en.wikipedia.org/wiki/X_Window_selection
  http://www.emacswiki.org/cgi-bin/wiki/CopyAndPaste

** xclipboard.

The xclipboard command emulates the traditional Macintosh style clipboard by
claiming ownership of the CLIPBOARD selection and answering any requests for
its value. When it loses the selection, it immediately asks the new owner for
the value of the CLIPBOARD selection, makes a local copy, and then reasserts
ownership of the CLIPBOARD. This way the clipboard contents can persist after
the original application has exited.