ZMARCO is an Open Archive Initiative Protocol for Metadata Harvesting (OAI-PMH) 2.0 compliant data provider. The 'Z' in ZMARCO stands for Z39.50; 'MARC' stands for MAchine-Readable Cataloging; and the 'O' stands for OAI.
VB-ZOOM is an ActiveX COMponent, written in Visual Basic, which is an implementation of the ZOOM (Z39.50 Object-Orientation Model) Abstract API (http://zoom.z3950.org/). It is a wrapper for the YAZ Toolkit from Index Data (http://www.indexdata.dk/yaz/). Windows 32-bit only; must use a 32-bit compatibility mode under a 64-bit version of Windows.