There is a new and more architecturally pleasing PDFBox.
There is a good old curve iTextPdf. But they don’t like the curvature of something ... The abundance of different classes for one task ...
Its iTextSharp port for .NET is especially nightmare, where there are not even tutorials really, but I already realized that you need to edit PDF in Java (or first in Java, and then transfer to .NET via IKVM).
What is better or which alternative would you prefer with the current level of libraries?
