Pretty powerful tooltips
tipsy
Facebook-style tooltips plugin for jQuery
BeautyTips
BeautyTips is a jQuery tooltips plugin which uses the canvas drawing element in the HTML5 spec to dynamically draw tooltips (sometimes called "talk bubbles" or "help balloons") associated with a html element on the page.
needim/noty
noty is a jQuery notification plugin that makes it easy to create alert - success - error - warning - information - confirmation messages as an alternative the standard alert dialog.
likeastore/ngDialog
Modals and popups provider for Angular.js applications
aui/artDialog
nakupanda/bootstrap3-dialog
Make use of Twitter Bootstrap's modal more monkey-friendly.
filamentgroup/dialog
Just a simple, minimal jQuery dialog with typical interactivity
vadimsva/popModal
jquery plugin for showing tooltips, titles, modal dialogs and etc
briceburg/jqModal
jqModal is a plugin for jQuery to help you display notices, dialogs, and modal windows in a web browser.
https://github.com/activebridge/lazybox
Lazybox is a jQuery-based, simple, lightweight lightbox that can display entire remote pages, images and confirmation dialogs. Replace standard rails confirmations with lazybox just added several rows to your project.