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.

DocuSign - Try DocuSign's interactive signing demo now! Send yourself an electronic document to digitally sign using our e-signature service.

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

WeSignature - WeSignature saves time, saves cost, and gives businesses the ability to obtain legally binding e-signatures from anywhere they have an internet connection.

PDFShift - Convert any HTML documents to high-fidelity PDF using a single POST request

VizanSign - Digital Signage Singapore