Thomas Habing's VB-ZOOM project is an ActiveX COMponent, written in Visual Basic, implementing version 1.2 of the ZOOM API.
It is built on top of Index Data's low-level YAZ Toolkit.
VB-ZOOM is available for free download from SourceForge at sourceforge.net/project/showfiles.php?group_id=53790
Jonathan Rowell points out the following pleasant accident:
Date: Thu, 21 Nov 2002 12:29:26 +0100
From: Jonathan Rowell <email@example.com>
Subject: Re: [ZOOM] C++ API and rawdata again
More details are available at its web site, vb-zoom.sourceforge.net