Imagefit is a simple, lightweight jQuery plugin to make images fit anywhere and anyway.
TextTailor.js is a jQuery plugin for responsive text to fill the height of the parent element or ellipse it when it doesn't fit.
Fit.js has a very simple purpose and that is to help you fit things into other things.
imgLiquid is a jQuery plugin to resize images to fit in a container.
Also Picbox WordPress plugin is now available.