Paperplane converts web pages to PDF documents. PDFs are rendered using Google Chrome, so the latest web standards can be used to author source documents. The API also allows you to convert multiple documents in parallel, and automatically uploads PDFs to cloud storage.
PDFShift - Convert any HTML documents to high-fidelity PDF using a single POST request
docassemble - docassemble is a free, open-source expert system for guided interviews and document assembly.
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
Knackly - Generate contracts, emails, or other documents of any complexity by automating your knack for doing...
HTMLEmail.io - Responsive HTML email templates for startups & developers
HotDocs - Template-driven, automated document & form assembly software