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.
wkhtmltopdf - wkhtmltopdf is an open source (LGPL) command line tools to render HTML into PDF and various image...
PDFShift - Convert any HTML documents to high-fidelity PDF using a single POST request
Tcpdf - TCPDF: Open Source PHP Class for generating PDF documents
PDF my URL - PDFmyURL turns any webpage or even complete website into PDF. Use our rest API in PHP, .NET, Ruby, Perl or any other programming language. Or convert webpages or even full websites directly in the browser!
HTML2PDF.fr - HTML2PDF is a HTML to PDF converter that allows the conversion of valid HTML 4.