rolling.html: Add GPL note, with links to the Git repository.

diff --git a/rolling.html b/rolling.html
index 6adbf5c..b5d3618 100644 (file)
--- a/rolling.html
+++ b/rolling.html
@@ -194,6 +194,20 @@ will be in millimetres; if you use inches, the results will be in
 inches.  Whatever you use, the results are displayed to only 3 decimal
 places.
 
+<h3>Code</h3>
+
+<p>The code which makes this page work
+is <a href="http://www.gnu.org/philosophy/free-sw.html">free
+software</a>.  You
+can <a href="http://git.distorted.org.uk/~mdw/dep-ui/">browse or download
+it</a>, modify it, and/or redistribute it under the terms of the
+<a href="http://www.gnu.org/licenses/old-licenses/gpl-2.0.html">GNU
+General Public License, version 2</a> or, at your option, any later
+version.
+
+<p>If you make interesting changes, I'd be very grateful to know about
+them.  Please <a href="mailto:mdw@distorted.org.uk">mail me patches</a>.
+
 </div>
 </body>
 </html>