Typefont
The first open-source library that detects the font of a text in a image.
Cufon
Fast text replacement with canvas and VML - no Flash or images required.
Big Text
jQuery plugin, calculates the font-size and word-spacing needed to match a line of text to a specific width.
Math Jax
Beautiful math in all browsers
Baseline.js
A simple jQuery plugin for restoring vertical baselines thrown off by odd image sizes
Flow Type.js
Web typography at its finest: font-size and line-height based on element width.
Text Tailor.js
jQuery plugin, tailor made text to fill the height of the parent element or ellipse it if it doesn't fit
Balance Text
A jQuery plugin for implementing balancing of wrapping text in a web page
Author Marks
JavaScript to toggle highlighting HTML5 'mark' tags, to emphasise con tent.
Kerning.js
Take control of your web typography.
Jquery.typer.js
A simple jQuery plugin for a slick typing effect.
Fit Text.js
A jQuery plugin for inflating web type
Blast
Blast text apart to make it manipulable.
jQuery Webfonts
jQuery based Webfonts library
Webfontloader
WebFont Loader gives you added control when using linked fonts via @font-face.
Trmix
apply CSS based on your browser's text rendering engine
Lining.js
An easy to use javascript plugin offers you complete DOWN-TO-THE-LINE control for radical web typography.