Highslide JS is an image, media and gallery viewer written in JavaScript. These are some of its advantages:

• Quick and elegant looking.
• No plugins like Flash or Java required.
• Popup blockers are no problem. The content opens within the active browser window.
• Single click. After opening the image or HTML popup, the user can scroll further down or leave the page without closing it.
• Lots of configuration options and scalability without compromizing on simplicity. A component system lets you strip away unused features down to a filesize of 10kB.
• Outstanding, unconditional and free user support for both commercial and non-commercial users.
• Compatibility and safe degrading. If the user has disabled JavaScript or is using an old browser, the browser redirects directly to the image itself or to a given HTML page.
• Source code included.

Get Source here