impress.js is a client-side JavaScript presentation framework that leverages CSS3 3D transforms and transitions to create dynamic, Prezi-like slideshows. The core library manages step navigation, camera positioning, and event handling, exposing a simple API (`impress().init()`, `next()`, `prev()`, `goto()`). It features a plugin system where each plugin is a separate file under `src/plugins/`, communicating via events. Plugins add functionality such as autoplay, markdown rendering, speaker console, touch/swipe navigation, and relative positioning. The build process (`build.js`) concatenates the core and all plugins into a single distributable file (`js/impress.js`) and minifies it with Terser. The repository includes multiple example presentations demonstrating various features, a QUnit test suite, and CI configuration. There are no runtime dependencies; the library is designed to work in modern browsers with CSS 3D support. The codebase is well-structured with clear separation of concerns, though some tooling (jshint, jscs, ESLint 6) and a Node requirement of >=7.6 indicate moderate technical drift.