The ImageSlider extension provides a simple, dependency‑light before/after comparison slider for two images using a parser function.
It supports both vertical (left/right) and horizontal (up/down) reveal modes, is keyboard accessible (ARIA slider, arrow keys, Home/End), touch/mouse friendly, and adds no external libraries.
Based on the FürthWiki implementation by Mark Muzenhardt.
See the full documentation on mediawiki.org.
