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.
Jekyll is a blog-aware, static site generator for personal, project, or organisation sites.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Umami is a self-hosted web analytics solution. It's goal is to provide a friendlier, privacy-focused alternative to Google Analytics and a free, open-sourced alternative to paid solutions.
Varnish is a reverse caching proxy.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.