CloudFlare - Cloudflare is a global network designed to make everything you connect to the Internet secure, private, fast, and reliable.
jsDelivr - A free, fast, and reliable Open Source CDN for npm and GitHub with the largest network and best performance from all OSS CDNs. Serving 100 billion requests per month.
Paessler PRTG - An advanced network monitoring solution to monitor network up/downtime, traffic and usage.
Statically - The free optimization & CDN for images, CSS, JavaScript, and open source.
MRTG - MRTG (or Multi Router Traffic Grapher) is an open-source network monitoring tool.
raw.githack.com - raw.githack.com serves raw files from github.com with proper Content-Type headers (like rawgit.