cdnjs is a free distributed JS library delivery service.
Google Maps is a web mapping service. It offers satellite imagery, aerial photography, street maps, 360° interactive panoramic views of streets, real-time traffic conditions, and route planning for traveling by foot, car, bicycle and air, or public transportation.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Materialize CSS is a front-end framework that helps developers create responsive and mobile-first web applications. It is based on Google's Material Design guidelines.
Netlify providers hosting and server-less backend services for web applications and static websites.
Wufoo is an online form builder that creates forms including contact forms, online payments, online surveys and event registrations.