Delphi can generate DLLs, which can be called from C, C++, Visual Basic,
Powerbuilder, or anything else that understands standard Windows DLLs.
There is an example of a database-capable DLL in the DEMOS\DB\DLL
directory.
As is the case in all Windows programming languages that I know of, DLLs
are difficult to debug and will crash your system if they aren't quite
right. Save your source code frequently.