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.
Rainforest API - Rainforest API is the real-time Amazon Product Data API you've been looking for. No manual rules or web-scraper maintenance required.
PDFShift - Convert any HTML documents to high-fidelity PDF using a single POST request
cloudlayer.io - Automate your content generation
Tcpdf - TCPDF: Open Source PHP Class for generating PDF documents
MXGuardian.net - Spam filtering that just works