If you only want to display images: Lightbox 2 - the original, by Lokesh Dhakar, is a "simple, unobtrusive script used to overlay images on the current page. It's a snap to setup and works on all modern browsers."
Framework: prototype, scriptaculous
Displays: images (with transition effects)
Lightbox ++ - based on the original Lightbox but provides more options for image re-sizing based on browser window size.
Framework: none
Displays: images
Litebox - a code-reduced version of Lightbox, uses the moo.fx library and prototype-lite. A good choice if page weight is a concern.
Framework: Prototype Lite, moo.fx
Displays:images
Slimbox - a lightweight variation of the original Lightbox, built on mootools.
Framework: mootools,
Displays: images
If you want to display html, forms, flash, video etc.:
Thickbox is a "webpage UI dialog widget written in JavaScript on top of the jQuery library. Its function is to show a single image, multiple images, inline content, iframed content, or content served through AJAX in a hybrid modal."
Framework: jQuery
Displays: images (no transitions but will resize images if larger than browser window), inline, iframe or ajax served content.
Lightbox Gone Wild! can be used to provide additional info, show an image or present a form for user input.
Framework: prototype
Displays: images, html, forms etc.
Multi-faceted Lightbox - prototyped based again, but offers a variety of options for different types of data that can be loaded in the lightbox.
Framework:none
Displays: images, html
Leightbox - very similar to Lightbox Gone Wild (prototype based, allows images, html etc) except that Leightbox keeps the lightbox content in the html, but hidden from view, so that it can be indexed by search engines.
Frontbox - self-contained script that doesn't rely on any other frameworks; degrades well, lightweight, cross-browser and can display images, html, ajax served content and hidden divs.
Framework: none
Displays: images, html, ajax-served, hidden divs
Lytebox - based on original Lightbox script but written to eliminate the need for the prototype and scriptaculous libraries.
Framework: none
Displays: Images (including slideshow option) and html content.
Bumpbox - an ajax lightbox script that can display images, html content, PDF's, remote content etc.
Framework:mootools
Displays: Images, html, pdf's, flash (in limited browsers), remote content
Lightbox++ - lightbox clone that's built to handle Flash as well as regular images.
Framework: prototype, scriptaculous
Displays: Flash, images
iBox - super lightweigh script that handles Images, inline divs, and external HTML pages, without any external libraries.
Framework: none
Displays: images, divs external html.
YUI Based Lightbox - a lightbox script built on Yahoo User Interface Library
Framework: YUI Library and dependencies
Better Modal Window - prototype based script that uses a hidden div in the html as content source for the lightbox.
Framework:prototype
Displays: anything you can put in a div.
Misc: Almost CSS Only Lightbox - the author calls it a CSS Only Lightbox, but it's not quite that. It is mostly, only CSS though :)
Suckerfish Hover Lighbox - lightbox effect while keeping accessibility. Not classic lightbox-ish but a nice presentation, nonetheless.
Un-named Lightbox Variant - based on Version 1 of the original Lightbox script, this one adds subtitle and fullsize support, hides forms and Flash objects and works even when JS isn't on.
Execute Lightbox Scripts from Flash - a how-to.
AJAX for lightboxes - an informative article on bringing AJAX to lightboxes.
Add-ons to other scripts: Slightbox - adds lightbox functionality to
JonDesign's SmoothGallery.
Lightbox 2 for Wordpress - bring lightbox functionality to WordPress based sites with this script built on prototype and scriptaculous.
Textpattern Lightbox - lightbox script for Textpattern based sites.
Greased Lightbox - greasemonkey, creammonkey and Opera user script for adding Lightbox functionality to sites like Flickr, DeviantArt, My Space, Wikipedia
Galri - lightbox add-on script for Picasa
Did I miss any? Let me know via my contact form.
Added:
Highslide JS - a simple thumbnail viewer script that differs from traditional lightboxes, in that it doesn't prevent the user from scrolling the containing page. It also degrades nicely and doesn't require any additional framework install. (Thanks Trevor, for passing this one on!)
Added:
jQuery Lightbox which is an images only port of Lightbox 2 built on the jQuery Library. (thanks Tom for sending this link along!)
from :
http://www.fortysomething.ca/mt/etc/archives/006978.php & usefull proxy -
http://www.d44.info/