Build modern reactive terminal applications for data workflows in R using reusable widgets, layouts, events, focus management and themes. A virtual screen buffer and incremental rendering update changed cells, while a headless driver supports deterministic application tests. Includes data tables that render visible rows on demand, lazy table sources, data inspection, SQL editing and background R workers with progress and streamed output. Optional database support and static text, Markdown, HTML, SVG and JSON exports support analytical tools and reports without requiring an interactive terminal for static output.