AddThis is a social bookmarking service that can be integrated into a website with the use of a web widget.
Cloudflare is a web-infrastructure and website-security company, providing content-delivery-network services, DDoS mitigation, Internet security, and distributed domain-name-server services.
Fastly is a cloud computing services provider. Fastly's cloud platform provides a content delivery network, Internet security services, load balancing, and video & streaming services.
GitHub Pages is a static site hosting service.
Gravatar is a service for providing globally unique avatars.
HTTP/3 is the third major version of the Hypertext Transfer Protocol used to exchange information on the World Wide Web.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Varnish is a reverse caching proxy.