Peter,

>>Other reasons are number of work areas available, using alias's that make sense instead of unqiue alias' so the work areas can be told apart,
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>This one I don't get. Could you elaborate?

If you are using the default data session for all fomrs and you have, say, an invoice and a customer form that are not related to each other. Both of these forms need the Customer table opened and if you want to keep them separate you need to open each instance of the customer table with a different alias, meaning that in at least one of the forms the alias will not be Customer.

As for number of workareas, VFP gives us 32,767 work areas ... per data session. That is every form or report that has a private data session has its own 32,767 work areas available.

>>testing multi-user code an a single machine, when you get to DLLs and COM servers keeping one server form stomping on the data of another ...
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>I've been told that COM object have no UI. Confused again...

Having a UI has nothing to do with using a Private data session. Most of my COM servers are subclassed from the VFP form simply so I can give them a private data session. Now, with S)P3 I am shifting to using the Session calss for this purpose.