Open source PDF generation with iTextSharp

iTextSharp is an open source project based on iText that lets you generate PDF files on the fly. Its functionaliy only slightly overlaps ExpertPDF; it's more for creating PDFs entirely from code, while ExpertPDF is more about manipulating existing PDFs or creating new ones from HTML. iTextSharp has very limited support for HTML to PDF conversion; it won't work on anything but the simplest HTML documents.