This article shows you how to convert a multipage TIFF to PDF using PDFKit.NET
In the following code sample you can see how you can easily merge PDF files into one. It creates a new document and then adds a clone of the pages from each input document. Please take note that the input files will not be read until they are needed, so you can only close the input files until a copy has been made by writing the new document to the disk. This is done for efficiency: if you import a 1000-page document and only need the first page containing a certain keyword, then the rest of the pages will not be processed.
The following code sample shows how to split PDF pages in C# and VB.NET
Import a digital signature and sign a PDF.
This code sample shows how to create bookmarks in an existing PDF document.