In this article, we will talk about three PDF Generating libraries that developers must know for PDF modification purposes. One of the main problems with PDFs is that it's difficult to modify them. The IronPDF library can be used to create, edit and manipulate PDF files with just a few lines. IronPDF is a highly performant.NET PDF library that has an API that's been optimized for use with other Microsoft technologies. The library has features that make it easier for developers to create secure, convenient and customizable HTML to PDF conversions.