Literary pop-ups from Keats's 1819 odes
Nightingale is an extension designed for people who want to periodically see snippets from the poetry of John Keats as they browse the web.
As you browse, Nightingale looks for semantic, syntactic, and prosodic echoes between Keats's poetry and the page you are on. If it finds one, some text on the page will glow. Hovering over the text will trigger a pop-up containing the quotation from Keats that echoes it. Clicking on this pop-up will open a new window containing the original poem. Hovering over the glowing words once more will make the pop-up disappear.
Nightingale remembers which Keatsian quotes you have recently stumbled upon and tries to give you fresh ones. If you read a quote for at least ten seconds, Nightingale will give you a break and not show you any more pop-ups for several days.