Allowing Annotations to PDF Files with Delphi Application

Hello,

I was wondering -- is there any VCLs or components or code out there
that allows you to add annotations to PDF files?  I have an application
that includes that ability of users to open and view PDF files.

I need to provided them the added-ability to also markup and add
annotations to the PDF files.  I don't have the Adobe Acrobat software
so I can't use the distiller or exchange applications (or whichever ones
does it).

If not -- does anyone know where I could obtain information about how to
add annotations to PDF files?  I have searched the web but there doesn't
seem to be much on markup / annotations for PDF files.

Also, I have seen a lot of references to PasPDF on Geocities -- but when
I try the link that page seems to have disappeared.  Does anyone know
any other place that I could get this Unit / VCL?

Thanks,

Hugh