diff --git a/org.fortiss.tooling.spiderchart.ui/html/developer/.ratings b/org.fortiss.tooling.spiderchart.ui/html/developer/.ratings
index de514d466b4389ae4196edeed7d6645a6f754b9b..fbc42e310ecc4e1fbc167e2d36ddd43003447567 100644
--- a/org.fortiss.tooling.spiderchart.ui/html/developer/.ratings
+++ b/org.fortiss.tooling.spiderchart.ui/html/developer/.ratings
@@ -1 +1 @@
-documentation.html 76dffdc2a7b31a074110e65d21ded439964639cd RED
+documentation.html 986e2dea49f3e82df111a62b03fc52237f5593bd YELLOW
diff --git a/org.fortiss.tooling.spiderchart.ui/html/developer/documentation.html b/org.fortiss.tooling.spiderchart.ui/html/developer/documentation.html
index 76dffdc2a7b31a074110e65d21ded439964639cd..986e2dea49f3e82df111a62b03fc52237f5593bd 100644
--- a/org.fortiss.tooling.spiderchart.ui/html/developer/documentation.html
+++ b/org.fortiss.tooling.spiderchart.ui/html/developer/documentation.html
@@ -1,4 +1,16 @@
-<html><body>
-<H1>Developer Documentation for <I>org.fortiss.tooling.spiderchart.ui</I></H1>
-<P>// TODO
-</body></html>
+<html>
+<body>
+<h1>Developer Documentation for Tooling Spider Chart UI (<i>org.fortiss.tooling.spiderchart.ui</i>)</H1>
+<p>This plugin provides a spider chart (also: radar chart) viewer (used to visualize multivariate data such as
+Pareto optimal solutions).</p>
+<p>It consists of the following packages:
+<ul>
+<li><code>model</code>: <code>SpiderChart</code> data model and support classes.</li>
+<li><code>style</code>: Style definitions (axes, chart, colors, data series, fill, font, legend, lines).</li>
+<li><code>util</code>: Utility methods.</li>
+<li><code>widget</code>: <code>SpiderChartViewer</code> and support classes.</li>
+
+</ul>
+</p>
+</body>
+</html>