fans using Firefox can opt for either or . These two Firefox add-ons transform the Firefox interface, stripping away much of the UI chrome and leaving you with a very minimal browser packing lots of hidden shortcut keys. Vimium, by contrast, leaves the Google Chrome user interface unchanged, and doesn't even add a button to the toolbar. In other words, if you don't already know it's there, you may not even notice it. This is nice if you share Chrome with another user who likes the default interface and uses the mouse and built-in keyboard shortcuts for everything.
Some of the functionality Vimium provides is already baked into Chrome. For example, you can use Vimium to switch tabs using gt (switch to the next tab) and gT (switch to the previous one), but Chrome already has Ctrl+PgUp and Ctrl+PgDn for that. The same goes for H, "go back in history," which is provided by Backspace by default. Fortunately, the default Chrome shortcuts keep on working with Vimium installed. Also, Chrome has no shortcut for "go forward"; Vimium does (L, by default).
Vimium shines when it comes to more complicated features. For example, hit ]] (closing bracket, twice) to switch to the next page on a list of search results. Hitting [[ will take you to the previous page. And if you want to open links without using the mouse, just tap f: Every link on the screen will be tagged with a little label bearing two or three letters. Type those letters, and the link instantly opens. If you want the link to open in a background tab, start by typing F (Shift+f) instead of f. This is similar to the way old Firefox add-on Hit-a-Hint worked.
Ironically, one of the main things holding Vimium back is Google's own fondness of Vim-like keyboard shortcuts. Many Google services, such as Gmail, Google Reader, and even the YouTube Flash video player, feature their own set of keyboard shortcuts. Many of these shortcuts overlap Vimium's, which means Vimium must be disabled on those websites. This can make for a jarring user experience: Use gT to flip between tabs until you get to a tab that contains a Gmail session ... and then you're stuck. The shortcut just stops working, because Vimium is disabled for that tab. By default, Vimium doesn't work on Gmail and Google Reader, and you can add other sites to the list.
The two main features that make Vimium attractive are being able to quickly open links and advance to the next page in a paginated article using just the keyboard. If these are things you've always wanted to do, take Vimium for a spin--you may like its other features, too.