This repository provides a self-contained, single-file JavaScript library that renders an interactive SVG technology radar (aka 'tech radar') using D3.js v7. The radar visualizes technology entries arranged in concentric rings (e.g., ADOPT, TRIAL, ASSESS, HOLD) within four quadrants. Entries are positioned using a D3 force simulation to avoid overlap, and they support hover tooltips, hyperlinks, and visual indicators for movement (new, moved in/out). The library is configurable via a single `radar_visualization()` function that accepts a JSON configuration object specifying dimensions, colors, rings, quadrants, and entries. It is designed as a client-side library included via `<script>` tags and is served as static HTML. The codebase consists of a single monolithic JavaScript file (`radar.js`) with no modular decomposition, tests, or build pipeline. While well-implemented and functional, it lacks modern JavaScript modularization and testing infrastructure. The repository also includes historical release versions and a sample configuration (`config.json`) used by Zalando's own Tech Radar. There is no backend, data pipeline, or research component; it is purely a front-end visualization tool.