 the windowing system, including image windows and, if necessary, a
text window.  This document describes the DLL interface, which consists of
eight main functions, <a href="#functions">seven platform-independent
ones</a> provided by the DLL and one, <a href="#Callback">the callback
function</a>, provided by the caller.  The DLL provides some other
platform-specific functions for display devices.

<p>
The DLL's name and characteristics differ among the three platforms:

<ul>
<li>The <a href="#OS2_device">OS