featherlight

Featherlight is a very lightweight jQuery lightbox plugin. It's simple yet flexible and easy to use. Featherlight has minimal css and uses no inline styles, everything is name-spaced, it's completely customizable via config object and offers image, ajax and iframe support out of the box. Featherlights small footprint weights about 4kB – in total. Maintained by noelboss on GitHub, where it has earned 2,077 stars from the community.

It's actively developed around ajax, javascript, jquery, and is a solid reference for anyone building with these tools.