On the page at
dev.ardupilot.com/wiki/table-of-contents/
the link that displays as “Setting up SITL on Linux” is broken. In the page source there are two hrefs, one correct one incorrect, but only the incorrect one actually displays. In the page source the incorrect link looks like this
the other correct one that does not display is
Tested and observed same results it in Chrome Version 35.0.1916.153 on Mac OS X 10.9.3 and Windows 8.