
Foxden has an extremely simple language that allows you to split up a window into rows and columns and put a different url in each.
The URL is usually a productivity webapp you use regularly, such as your webmail, a calendar, a TODO list, Remember The Milk, your bug tracker, Twitter, anything really.
The URL can also be a local file, in which case Foxden wraps it in an editor widget, so you can takes notes locally.
Or the URL can be a 'chrome' URL, if you know what you're doing. You can embed Firefox inside a Foxden pane.