Type.js adds new type properties to your CSS, giving you the control you need for type on the web. You can write these properties in your CSS and they will work like any other property.
FlowType.JS is a plugin for Responsive Web Typography at its finest: font-size and line-height based on element width.
FlowType.JS is changing the font-size—and subsequently the line-height based on a specific element's width. This allows for a perfect character count per line at any screen width.