To create a side-bar we need two things; an XHTML document that will provide the functionality of the side-bar, and an installer that will wire the side-bar into the browser. The XHTML document we will use is the del.icio.us bookmarking form that we create in the Introduction to XForms. We'll use this partly because it's a useful form, and partly to show that any XHTML document can be used as a side-bar.
The installer will have to be created from scratch, but since it is just a normal XForm we can use the usual template as our starting-point. We'll begin by setting the document's title:
<title>Soft-bar Installer</title>
</head>