I am trying to develop an MSSQL ASP application that ties real-time into customer's existing databases at remote locations. The customers use everything from IBM mainframes to SQL or Oracle, and the data needs to flow both ways. Is XML the best fit for this application? Are there any software packages available that could prevent me from having to custom write each script?
This depends very much on whether the Oracle and IBM systems themselves expose XML. If they do, then I would strongly recommend that you investigate the possibility. Oracle 8i contains extensive XML support. Also, the newer IBM DB2 implementations are moving toward XML representations.
The key would essentially be to write XSL scripts that handle the conversion between different database representations. However, these would be far easier than trying to write ASP scripts and remote procedure calls.