This repository provides a self-contained JavaScript library (`radar.js`) that renders an interactive 'Tech Radar' visualization using D3.js v7. The radar chart displays technology entries organized into four quadrants and four concentric rings (e.g., ADOPT, TRIAL, ASSESS, HOLD), with automatic collision-avoidance positioning via D3's force simulation. The library is used by Zalando to visualize their internal technology choices and is published as a static page. The codebase consists of a single global function (`radar_visualization`) that accepts a configuration object, making it easy to embed in any HTML page. It includes features like hover tooltips, clickable links, a legend with text wrapping, optional ring description table, and a print layout mode. The repository also contains historical release versions of the library. It is not a data pipeline or research project; it is a purely client-side visualization tool.