Q:
I’m deciding between using the PDFNet SDK and one of the tools SDKs. What are the differences between them?
A:
The PDFNet SDK is a full-featured toolkit for creating, viewing, converting, and editing PDF documents. It can edit and flatten annotations and merge XFDF documents. It is available on a variety of desktop, server, and mobile platforms.
The tools SDKs are much more limited, and provide only the functionality provided by the command-line tools (http://www.pdftron.com/pdftools.html). They thus have a lower learning curve.