capybara-webkit depends on a WebKit implementation from Qt, a cross-platform development toolkit. You'll need to download Qt to build and install the 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.
capybara-webkit is Copyright © 2011 thoughtbot, inc. It is free software, and may be redistributed under the terms specified in the LICENSE file.