What are my options to merge PDFs in a web site or web service environment?

Question

I have multiple PDFs coming from a report generator and I want to merge them to a single document. The merging process must run in a web site or WCF web service environment (Framework 4.0, IIS 7.5). Is there a component, open source or commercial, to accomplish this?

In my process I get the PDFs as streams. If I have the choice, I would prefer a merging method, working directly on these streams - without file representations.

Also memory consumption could be an issue. My PDF files can be large.

Answer 1

There is a list of PDF libraries here: http://stackoverflow.com/questions/210029/pdf-libraries

Answer 2

I solved this issue using iTextSharp. My solution follows a similar solution on The Code Project.

iTextSharp makes it very easy to use streams instead of files.