romainguillaume

This plugin targets menus anchors. Then when any gets clicked, this plugin makes the document scroll smoothly to the targeted element.
It is using a native Javascript function that works in many browsers. Note that some browsers will not display the scrolling smooth animation and only point the targeted element without animating the scrolling.

Libre scrolling

Triggers when a anchor of a menu is clicked ; scrolls smoothly to its targeted element.

corybolles

The Mythic Smooth Scroll plugin is a very lightweight jQuery plugin for adding smooth scrolling animations on single-page websites or on longer posts with various anchors.
The plugin features an optional offset for fixed/sticky headers to make sure it always scrolls beneath the content, as well as an adjustable manual offset amount to determine how far from the header/top of the screen the content will land when scrolled to.

Mythic Smooth Scroll

Smooth scrolling plugin with optional offset for fixed/sticky headers.

Libre scrolling vs Mythic Smooth Scroll