Albert,

>Actually, I have a project where it'll be done with .NET. My understanding
>(which may not be entirely correct ) is that internally most .NET applications use
>ADO/XML and various XML and ADO methods to do the things that we'd used cursors
>for in VFP.

You'll need to get acquainted with ADO.NET, so picking up a good book on that is a necessity to understanding .NET's way of working with data. In .NET (in the simplest scenario), you use ADO.NET to query data from a backend database (or from VFP tables via OLE-DB driver) into an in-memory DataSet, which can have one or more DataTable objects inside it.

The DataSet and DataTables have properties and methods that allow you to manipulate how the queried-up data is presented in controls that you bind the data to, such as a grid control, allowing you so apply filters, sorts and so forth. However, you always want to keep the size of the data queries to a minimum and only bring in the data you need -- not the entire table as you might be accustomed to doing in Fox.

The DataSet can very easily spit out an XML representation of the data currently "inside it", which can be sent via a Web Services call or COM Interop call to a VFP component, where XMLAdapter can "un-XML" it into VFP cursors, so you can do some interaction with legacy VFP code if necessary while keep most of the application in .NET. That type of data interchange is where you'll most often "see" XML being used in .NET's data strategy.

>Doesn't sound very promising to someone used to VFP cursors...

It's different, but still very functional once you get used to it. Later versions of .NET will introduce more VFP-like manipulation of data once inside the DataSet, such as further SQL queries into the data subset, but that's probably a couple of years out.

Just follow the principles of client-server application development, which lead you to querying just the data you need at any given point in time, and you'll find response time pretty good. Try to load up massive amounts of data into DataSets for further manipulation, and you may hit some performance problems.