IDE Integration packs contain the nessesary files to compile a Win32 VCL based IDE add-in for either C#Builder 1 or Delphi 8. They contain the nessesary Win32 Delphi compiler and .dcp files in order to only build IDE addins.
For Delphi 8:
http://codecentral.borland.com/codecentral/ccweb.exe/listing?id=21333
For C#Builder 1.0:
http://codecentral.borland.com/codecentral/ccWeb.exe/listing?id=21334
There are also two new files in addition to the changes made to ToolsAPI.pas; PaletteAPI.pas and PropInspAPI.pas. These two files describe the APIs to the new Tool Palette and the Object Inspector, respectively.
Please note that these are provided as-is and are unsupported.
You will be required to click through a license stating this in order to download the files. Make sure you do not mix the C#Builder version with the Delphi 8 version and vice-versa. Also, an IDE add-in built with the files from the C#Builder integration pack will not work on Delphi 8. The same holds for IDE add-ins built with the Delphi 8 version cannot be used with C#Builder.
The version of the Win32 VCL shipped with Delphi 8 is different that the Delphi 7 and may contain some subtle differences in behavior and properties.
Any bug reports should be made through Quality Central.