The demo simply uses the luxy.js plugin: https://min30327.github.io/luxy.js/ https://min30327.github.io/luxy.js/ This is mentioned in the first sentence of the

The demo simply uses the luxy.js plugin: https://min30327.github.io/luxy.js/ https://min30327.github.io/luxy.js/ This is mentioned in the first sentence of the article: "Momentum (aka. smooth or interia) scrolling plugins (example here), while marketed as enhancements, are a plague upon the internet." The article author did not create these plugins.