Lightning (was Lightning Web Browser) is a minimalist web browser designed with one thing in mind - speed of search. An order of magnitude smaller than other browsers, Lightning loads in less than a second and is ready to use straight away. Enable the "Lightning Lookup" service and search on selected text from any application in an instant by typing command-@.
Based on Webkit (the already fast core of the Safari and Chrome browsers), instead of unloading browsed pages as you navigate, Lightning keeps a buffer of many WebBrowser objects in memory. This allows you to return back to a previously viewed page instantaneously without having to wait for it to reload. This optimisation makes a huge difference to speed of navigation. URL's (starting with http://) or search items can be selected or entered into the address bar. For search terms, select the site you wish use as a search engine on the popup list at the left hand side.