DocGen - Static website generator
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
openSourceCM - Web-based legal document processing and contract management
Document .Net - Gives you API to do everything with a document in PDF, DOCX, DOC, RTF, HTML and Text formats.
LogicalDOC - A document management system such as LogicalDOC can help your organization better manage business processes and put order in the chaos of documents every day run your business.
iTextPDF - iText offers flexible tools for PDF creation, editing and inspection.