Software that provides client access to OS/390 mainframes from Xbridge Systems, Inc., Mountain View, CA.  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.