A [capybara](https://github.com/jnicklas/capybara) driver that uses [WebKit](http://webkit.org) via [QtWebKit](http://doc.qt.nokia.com/4.7/qtwebkit.html).
capybara-webkit depends on a WebKit implementation from Qt, a cross-platform development toolkit. You'll need to download the Qt Framework to build and install the gem.
If you're on OS X, the installer at the above link will set up everything you need. You can download just the framework, as the full SDK isn't required to build the gem.