Bootstrap is a free and open-source CSS framework directed at responsive, mobile-first front-end web development. It contains CSS and JavaScript-based design templates for typography, forms, buttons, navigation, and other interface components.
D3 based reusable chart library
GoatCounter is an open source web analytics platform available as a hosted service (free for non-commercial use) or self-hosted app. It aims to offer easy to use and meaningful privacy-friendly web analytics as an alternative to Google Analytics or Matomo.
Heroku is a cloud platform as a service (PaaS) supporting several programming languages.
jQuery is a JavaScript library which is a free, open-source software designed to simplify HTML DOM tree traversal and manipulation, as well as event handling, CSS animation, and Ajax.
Progressive Web Apps (PWAs) are web apps built and enhanced with modern APIs to deliver enhanced capabilities, reliability, and installability while reaching anyone, anywhere, on any device, all with a single codebase.