to compile the worldviewer:
cd ${ROBOCUP_DIR}/robot/share
./makeDebug Debug.cfg
export PATH=$PATH:${ROBOCUP_DIR}/bin:${ROBOCUP_DIR}/robot/bin
cd ${ROBOCUP_DIR}/base/worldviewer/
make

to run the worldviewer:
./worldviewer

to use the worldviewer:
Settings->Ports
Add
Enter the team number of your robots (it's the second to last digit of the ip)
Ok
Ok