As a developer with an accounting degree, I see it is possible and economical to have a common platform for various accounting software to exchange electronic data. Some example transactions would be:
Customer / Supplier PO > Sales Order AP Invoicing < AR Invoice AP Payment > Apply Pmt AP/AR Reconciliation AP/AR Reconciliation etc.
I guess what I envision is a host db. Quickbooks, Peachtree, MYOB, Great Planes, etc. would have an interface to transfer data between their app to the host server. Suppliers/customers could receive transactions from the host server at their convenience.
The closest I came to what I had in mind is at