ViewerBox.js is a lightbox plugin, built with jQuery to satisfy my need for a lightweight and capable lightbox without a lot of the fluff or styling overhead that other more well-known plugins come with.
ViewerBox is built with responsive in mind and supports a gallery feature that will work with not only images, but videos and even iframe embeds (allowing for Youtube videos to be included). It is fairly lightweight too, and compatible with modern browsers.
Currently, ViewerBox is still under development and thus is lacking in documentation, as its feature set is not yet set in stone. The goal for finalising ViewerBox is to convert it to a fully fledged jQuery plugin, as well as for allowing for easy configuration and full control over the plugin. The styling for the lightbox is currently only available in SASS/SCSS format (and thus needs to be compiled into CSS).
It is available to download in its Github repository.