JavaScript librariesBrowser fingerprinting
FingerprintJS is a browser fingerprinting library that queries browser attributes and computes a hashed visitor identifier from them

CDN
Cloudflare is a web-infrastructure and website-security company, providing content-delivery-network services, DDoS mitigation, Internet security, and distributed domain-name-server services

Payment processors
Sell digital products and SaaS software the easy peasy way with Lemon Squeezy As your merchant of record we handle the tax compliance burden so you can focus on more revenue and less headache