Delphi since Delphi 6 comes with a file delphi.upg which is located in the bin directory.
This file is in .INI format and contains a list for replacing packages, which is used when upgrading a project from older Delphi versions.
It looks like this:
[Packages] cds= ... dss50=dss ibevnt50=ibevnt .... tlib30=tlib vclide30=vclide
As you can see, it contains entries from Delphi 3 (tlib30, vclide30 etc.) up to Delphi 5 (dss50, ibevnt50 etc.). The reason for this is that since Delphi 6 using a version suffix for .dcp filename is discouraged, while until Delphi 5 it was standard praxis. So in order for the Delphi ide to automatically upgrade packages from older versions to the new naming convention it uses this list.
Of course this is not officially documented but I just stumbled over this file and thought I should share my findings.
I guess it should be possible to extend this list to include e.g. the jcl/jvcl packages which have recently also switched from using version specific suffixes to the naming convention without version suffixes. --Dummzeuch 18:08, January 23, 2010 (UTC)