capybara-webkit depends on a WebKit implementation from Qt, a cross-platform development toolkit. You'll need to download the Qt libraries to build and install the gem.
If you're on OS X, download the non-debug Cocoa package. Note that installing Qt via homebrew takes more than an hour, so we don't recommend it.
If you're on Ubuntu, you can install the libqt4-dev package. For other Linux distributions, download this package.
If you're like us, you'll be using capybara-webkit on CI.
On Linux platforms, capybara-webkit requires an X server to run, although it doesn't create any visible windows. Xvfb works fine for this. You can setup Xvfb yourself and set a DISPLAY variable, or try out the headless gem.
Add the capybara-webkit gem to your Gemfile:
The capybara WebKit driver was written by Joe Ferris, Tristan Dunn, and Jason Morrison from thoughtbot, inc.
The names and logos for thoughtbot are trademarks of thoughtbot, inc.
This capybara WebKit driver will listen on port 8200, this may conflict with other services.
capybara-webkit is Copyright © 2011 thoughtbot, inc. It is free software, and may be redistributed under the terms specified in the LICENSE file.