The help website/knowledgebase (bitwarden.com/help).
The Bitwarden help center project is an open-source project that provides assistance and support for users of the Bitwarden password manager. It is written using Jekyll and can be accessed at https://bitwarden.com/help/.
Jekyll is a static site generator written in Ruby that allows you to create simple, fast, and secure websites without the need for a database.
Bootstrap is the most popular CSS Framework for developing responsive and mobile-first websites.
Gulp.js is an old but popular site building tool that automates various repetitive development tasks in web development, such as compiling Sass, minifying JavaScript, and optimizing images.