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
Online Convert - Convert files like images, video, documents, audio and more to other formats with this free and fast online converter.
ABCpdf.NET - ABCpdf.NET is a high-profile and powerful PDF Library that delivers the best experience possible for everyone.
Zamzar - Free conversion online of many type of documents (images, text, video, audio...
Document .Net - Gives you API to do everything with a document in PDF, DOCX, DOC, RTF, HTML and Text formats.
online2pdf - This Online PDF Converter can convert all your files to PDF but also compress and merge PDF files! Word, Excel, PowerPoint, images and any other kind of document can be easily converted to PDF on Online2PDF.