Document .Net - Gives you API to do everything with a document in PDF, DOCX, DOC, RTF, HTML and Text formats.
PdfPig - Read and extract text and other content from PDFs in C# (port of PDFBox)
iTextPDF - iText offers flexible tools for PDF creation, editing and inspection.
Wicked PDF - PDF generator (from HTML) plugin for Ruby on Rails
ABCpdf.NET - ABCpdf.NET is a high-profile and powerful PDF Library that delivers the best experience possible for everyone.
iText - iText is an intuitive and refined text editor with word processing completely rewritten in Cocoa...