cdnjs is a free distributed JS library delivery service.
Cloudflare is a web-infrastructure and website-security company, providing content-delivery-network services, DDoS mitigation, Internet security, and distributed domain-name-server services.
Howler.js is an audio library with support for the Web Audio API and a fallback mechanism for HTML5 Audio.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.
Unpkg is a content delivery network for everything on npm.
WebAssembly (abbreviated Wasm) is a binary instruction format for a stack-based virtual machine. Wasm is designed as a portable compilation target for programming languages, enabling deployment on the web for client and server applications.