The browsers that makes the entire Pali Canon, in Pali, accessible through a button on your browser's menubar. You have your choice of several different methods of transliteration; when you click on a Pali word, the definition of that word appears in a window below the text; and you have access, through the extension's browser window, to all available online Pali-English dictionaries. If there are translations of the sutta you're viewing available on the web, you have links to those. And that just begins to touch on its many features. For serious students of the Pali Canon, it's an invaluable tool. I've used it extensively in preparing my own translations of a number of suttas on (a support site for the classes I teach at our Osher Lifelong Learning Institute continuing ed. program at the University of Cincinnati and elsewhere).
"When one thing is practiced & pursued, ignorance is abandoned, clear knowing arises, the conceit 'I am' is abandoned, latent tendencies are uprooted, fetters are abandoned. Which one thing? Mindfulness immersed in the body." -AN 1.230