Nitro Pro - An affordable Adobe Acrobat alternative for editing and creating PDF
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
Adobe Acrobat DC - Make your job easier with Adobe Acrobat DC, the trusted PDF creator. Use Acrobat to convert, edit and sign PDF files at your desk or on the go.
Document .Net - Gives you API to do everything with a document in PDF, DOCX, DOC, RTF, HTML and Text formats.
PDF-XChange Editor - The smallest, fastest, most feature-rich PDF editor/viewer available
iTextPDF - iText offers flexible tools for PDF creation, editing and inspection.