MonsterWriter is a writing app that let's you focus on composing content instead of worrying about formalities. You do not have to move around headings and images form one page to the other. Inserting a new section at the beginning will not destroy the whole layout of your work. MonsterWriter follows the approach to separate the content composition and the typesetting - bringing the content to a printable page layout. The last part is done automatically by using LaTeX - the most powerful typesetting system available.
PDFCrowd - Pdfcrowd is a Web/HTML to PDF online service. Convert HTML to PDF online in the browser or in your PHP, Python, Ruby, .NET, Java apps via the REST API.
Overleaf - The online platform for scientific writing. Overleaf is free: start writing now with one click. No sign-up required. Great on your iPad.
DocRaptor - As the only API powered by the Prince HTML-to-PDF engine, DocRaptor provides the best support for complex PDFs with powerful support for headers, page breaks, page numbers, flexbox, watermarks, accessible PDFs, and much more
Fidus Writer - Fidus Writer is an online collaborative LaTeX editor especially made for academics who need to use...
PDFShift - Convert any HTML documents to high-fidelity PDF using a single POST request
Archimedes - Archimedes is a LaTeX and Markdown editor designed to make mathematical writing easy.