Minishowcase is a small and simple PHP/JavaScript online photo gallery, powered by AJAX that allows you to easily show your images online, without complex databases or coding, allowing to have an up-and-running gallery in a few minutes.
Using MooTools v1.11, this JavaScript gallery and slideshow system allows you to have simple and smooth (cross-fading…) image galleries, slideshows, showcases and other cool stuff on your website. Together there are 7 different gallery demos, You can download and test for free.
Unlike other systems out there, JonDesign’s SmoothGallery is designed from the ground up to be standard compliant: You can feed it from any document, using custom CSS selectors. And even better, this solutions is very lightweight: The JavaScript file is only 24kb.
Agile Carousel is a feature-rich jQuery plugin for creating attractive image sliders.
With a bunch of options to customize the slider, and it can be used with or without jQuery UI for more effects, the plugin provides total control.

From a folder mentioned, it gets the images via PHP (not Ajaxed).
A demo with all the features can be found here.