+cat head.html guide.head.html top-bar-gnu.html index.html.pre gnu-step.html rest.html footer.html > index.html
+cat head.html guide.head.html top-bar-mac.html index.html.pre mac-step.html rest.html footer.html > mac.html
+#cat head.html guide.head.html top-bar-win.html index.html.pre win-step.html rest.html footer.html > windows.html