HTML PDF API - Easily generate PDF documents from HTML code with our powerful API
PDFShift - Convert any HTML documents to high-fidelity PDF using a single POST request
Tcpdf - TCPDF: Open Source PHP Class for generating PDF documents
pdflayer - Free, powerful HTML to PDF API supporting both URL and raw HTML conversion. Unlimited document size, lightning-fast and compatible PHP, Python, Ruby, etc.
PDF-LIB - Create and modify PDF documents in any JavaScript environment
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.