Software that provides client access to OS/390 mainframes from Xbridge Systems, Inc., Mountain View, CA (www.xbridgesystems.com). Xbridge Professional runs in the mainframe and provides a TCP/IP link to a counterpart piece in a Windows NT/2000 server. It allows client access through the server to VSAM, DB2 and ISAM databases in the mainframe at the field level. Xbridge Systems was co-founded in 1994 by Gene Amdahl as Commercial Data Servers, a manufacturer of IBM-compatible mainframes. See CDS.