marker.js 2 - Image Annotation

marker.js 2 is a JavaScript browser library designed to enable image annotation functionality within web applications. It allows users to mark up, highlight, and add comments to images directly in the browser, and then save or process the annotated results. While still supported for some time, this version (2.x, with current stable being 2.32.7) is officially deprecated in favor of marker.js 3, which is the focus of all future development. Releases for marker.js 2 were frequent, often several patch versions per month, but this cadence is expected to slow significantly as focus shifts to v3. Its key differentiator was providing a complete, out-of-the-box UI for image annotation with various tools.