CurrencyFormatter.js allows users to format numbers in a variety of currency formats. It contains 155 currency definitions, and 715 locale definitions right out of the box, and can handle unusually formatted currencies, such as the INR and is completely configurable.
timeago.js is a tiny library used to format date with `*** time ago`. eg: '3 hours ago' with localization. No dependencies, support of automatically updating fuzzy timestamps.
jQuery.inputmask is a jquery plugin which create an input mask. An inputmask helps the user with the input by ensuring a predefined format. This can be usefull for dates, numerics, phone numbers, ...
jQuery JSONView is a plugin to view JSON in a more readable format. It offers some methods and options to customize.
Intl built-ins and industry-wide i18n standards, plus a set of integrations for common template and component libraries.
Mask.js is a simple functionality that you can use to force user met a pattern into inputs.