AddThis is a social bookmarking service that can be integrated into a website with the use of a web widget.
Buy me a coffee is a service for online content creators that they may use to receive tips and donations to support their work.
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.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Varnish is a reverse caching proxy.