Convert Select Box Into A Fully Styleable Dropdown List – Selectal.js
Selectal.js is a JavaScript plugin to replace the regular select box that enables you to style & control dropdown lists in a simple way.
JavaScript & CSS select
Smooth Touch-enabled Selectable Library – selection.js
selection.js is a pure JavaScript library which enables the smooth, touch-friendly selectable functionality on a group of DOM elements.
Powerful Single & Multiple Select Library – tail.select
tail.select is a rewritten version of the jQuery tail.select plugin that can be used to beautify & enhance the default select box with no dependency.
Easy Customization Of HTML Select Boxes – nice-select2
A pretty nice select box replacement library which converts the regular select element into an animated, customizable, searchable dropdown list.
Bootstrap Style Searchable Dropdown Plugin – fstdropdown
The fstdropdown JavaScript plugin turns a normal select element into a searchable, Bootstrap style drop-down select with pure JavaScript and CSS.
Custom Style Dropdown Select In Pure CSS – select-css
select-css is a CSS library that makes the styles of the native dropdown select consistent across browsers.
Elegant Multi-funtional Select Box Replacement – blob-select
blob-select is a blazing fast, easy-to-use and multifunctional select box replacement plugin implemented in pure JavaScript.
Beautify Native Select Elements With JavaScript – nativejs-select
nativejs-select is a vanilla JavaScript plugin to beautify the native select boxes with custom styles.
Popup Option Picker With Vanilla JavaScript – pickout
pickout is a Vanilla JavaScript library to enhance the default select box that allows you to select an option from a popup box.
Minimal Cascading Dropdown Menu In Pure JS – dependent-selects
dependent-selects is a minimal, unobtrusive JavaScript library for creating cascading drop-down menus.