Redis - Redis is an open source in-memory data structure project implementing a distributed, in-memory key-value database with optional durability.
PDFShift - Convert any HTML documents to high-fidelity PDF using a single POST request
Amazon ElastiCache - Amazon ElastiCache offers fully managed Redis and Memcached. Seamlessly deploy, operate, and scale popular open source compatible in-memory data stores.
KDAN Mobile PDF Reader - PDF Reader is the one app you can rely on when you need a portable solution to work with PDFs.
Athena - A community-curated repository of learning resources
PlutoPDF - A URL to PDF converter wrapped behind a simple API.