Yahoo! Axis! Of! Incompetence!
Axis works by providing a search box and performs as-you-type search feedback, familiar to anyone who has used Google in the last decade. The search results can be stepped through and images or thumbnails are rendered for search items in a way reminiscent of Apple's coverflow or Microsoft's Windows Mobile grid.
Almost no information is available from the axis.yahoo.com site, providing instead a video to demonstrate the capabilities.
This has been described by some as a 'browser', but that isn't strictly true; it doesn't replace any of the rendering contents that the browser otherwise handles. What it does do is allow you to 'browse' (i.e.: search) the internet by search keywords, much like walking through Yahoo! Directory! but with graphical previews.
As well as the application for mobile sites, there is an extension which can be plugged into desktop browsers such as Safari and Chrome. Unfortunately for the developers, the private key used to sign the Chrome extension was made available in the extension download itself, meaning that anyone can now sign Chrome extensions claiming to be from Yahoo! and make them available from the app store.
As a result, the recommendation is not to install any extensions that have been signed by Yahoo! into your browsers until Google releases an update which revokes the leaked key. More information on the disclosure is available from nikcub.appspot.com, and a proof-of-concept exploit has been made available on this GitHub repository. The private key is available for viewing here.