When you work with eclipse 64 bit on fedora 17-64 bit and JDK 64 bit, you can not use internal SWT web browser inside eclipse (and also some plugins features like GPE gwt uibinder designer or Vaadin visual user interface designer  which use this facility ) for solving this issue you can follow this steps:
  1. Run "sudo yum install webkitgtk" command from terminal.
  2. Go to "eclipse.ini" file (located in the root of eclipse installation directory) and add "-Dorg.eclipse.swt.browser.UseWebKitGTK=true" at the end of this file.
Have a nice time.