ISAPI Include: ISAPIconnect.inc
Constants:
Functions:
File IO: fileio.inc

Constants:
Functions:
Comments: Reduces time curve on using Scripting.FileSystemObject for file IO
Email: EmailProcessing.inc

Constants:
Functions:
File Upload: fullupload.inc

Constants:
Functions:
Database: Just reference the ADO.ASP file for ADO tips.

It is not required to use the include files but it may make development easier.