PDF Clown - PDF Clown is an open-source general-purpose library for manipulating PDF documents through multiple abstraction layers, rigorously adhering to PDF 1.7 Specification
Kdan PDF Reader - The All-in-One Document Expert Designed for the Increasingly-mobile Workplace.
Document .Net - Gives you API to do everything with a document in PDF, DOCX, DOC, RTF, HTML and Text formats.
PDFJet - PDFJet is a mobile and cloud PDF Library for Java and .NET to generate PDF documents.
ABCpdf.NET - ABCpdf.NET is a high-profile and powerful PDF Library that delivers the best experience possible for everyone.
Qoppa Software - Qoppa Software offers a suite of products that cover every aspect of PDF processes and integrate seamlessly into document workflows.