diff --git a/index.html b/index.html
index 8a94134..cd14e24 100644
--- a/index.html
+++ b/index.html
@@ -1,4 +1,22 @@
+
+
SuFoGraph - Super Formula Guilloché patterns
diff --git a/main.js b/main.js
index 47c797d..d074e2f 100644
--- a/main.js
+++ b/main.js
@@ -1,3 +1,20 @@
+/*
+ Copyright © 2017 Jeff Epler
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along
+ with this program; if not, write to the Free Software Foundation, Inc.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
var fix = function(d) { return d.toFixed(2); }
var todatauri = function(d, t) { return "data:" + (t || "") + ";base64," + btoa(d); }