Changing a Delphi/Oracle application from 2-tier to 3-tier

In my company they are finally (about time...) considering to convert one of our best selling apps from a 2-tier to 3-tier architecture, both on logical (Presentation, Business开发者_Go百科 and Data layers) as well as physical level. Probably we will go for either a Delphi-Delphi-Oracle or a Delphi-Java-Oracle approach for the change.

This is a relatively old and large app that has been created and modified for a long time before I began working there. Refactoring, except for when something had to be changed, was usually never considered. Also, business logic is present in both of the actual tiers... sigh.

The physical change does not bother me much but the logical change will be kind of a passage through Hell. In order to smooth it as much as possible I would like to investigate about which Delphi components suit better for a 3-tier model.

¿Which alternatives would you consider to use?

Another good n-tier framework library is kbmMW from components4developers: http://components4developers.com/

We've recently converted our 2 tier Delphi app to 3 tier using RemObjects DataAbstract. While the initial learning curve was quite steep, we are absolutely delighted with the results.

DataAbstract lets you forget about the underlying nuts and bolts of database and network connectivity and concentrate on the business logic. It allows you to create an abstract service layer that provides your server clients with a nice API. Using this API we connect to the server using both a Delphi and a Delphi Prism ASP.NET client.

I've found RemObjects pretty usable. They have also DataAbstract built top on it, but I haven't used it.

Have you ever considered DataSnap XE?