Inspired by lightbox and include the support for form and html. It is based on prototype and scriptaculous.

3. Colorbox

Lightweight and customizable lightbox plugin through CSS and jQuery. The plugin support images, image group, ajax, inline content and iframe content.

4. Fancybox

Display images, html and multimedia content. It is a jQuery based lightbox.

5. jQuery Lightbox Plugin

Similar to Lokesh Dhakar lightbox solutions, except it is jQuery based.

6. prettyPhoto

Jquery lightbox clone and support more multimedia format.

7. Litebox

Lightweight lightbox which built on moo.fx and prototype.lite.

8. Thickbox

Similar solutions to lightbox2, but it has more features like display inline content, iframed content or content served through ajax in a hybrid modal. It is build on jQuery.

9. Slightly Thickerbox

A mod from thickbox which add on next and previous button to form a images gallery.

10. Slimbox

The ultimate lightweight Lightbox clone for jQuery. As stated, slim and slimmer solutions for lightbox.

11. LightView

Built with prototype and scriptaculous. Supports plenty of media format.

12. jQuery Dialog

jQuery UI also contains dialog component, although its nature is more like a dialog and form. But, you can customize to create your own flavor of image preview or gallery.

13. Prototype Window

A prototype based window dialog.

14. MochaUI

MochaUI is an UI framework for mootools. It includes dialog windows for displaying rich content.

15. Facebox

Facebook lightbox aliked, jQuery based modal dialog. It support images, div or entire remote pages.

16. Boxy

Facebox aliked, but it support more features like dragging and size tweening.

17. ModalBox

A modal dialog that allow you to include html within. Build with prototype and scriptaculous.

18. Shadowbox

Support most of the media format and it is customizable through css. On top of that, it is a standalone javascript solutions. It is free for non-commercial usage.

19. LightWindows

A comprehensive lightbox solutions which enable you to embed images, video,iFrame, flash and more.

20. SimpleModal

Yet another jQuery based modal dialog.

21. jqModal

22. Multibox

Support images,flash, video, mp3 and html and it is build with mootools.

23. Greybox

Can be used to display websites, images and other content, doesn’t rely on any ajax framework.

24. Highslide

A really quick and smooth free image viewer. It supports plenty of formats like html,ajax,iframe and flash.

25. Sexybox

Another standalone lightbox which display content directly from html.

Lightbox Generator

VisualLightbox

WebGalleryCreator

Lightbox Plugins for Wordpress

Lightbox2

jQuery Lightbox

Shadowbox

Flexible Lightbox

If you need more lightbox plugin for wordpress, you can visit the link here.

Alternative Solutions

Creating Lightbox with CSS

Firefox hack – Greased Lightbox