CustomizingTestExecution [add child]
You may customize the way tests are executed to suite your needs. You can even change the language of execution!
The is done by defining any of a few special variables in the scope (see VariableScope) of the tests you wish to execute.
The special variables are:

COMMAND_PATTERN is the basis for every execution performed in FitNesse. It specifies the command that will be executed.
default: java -cp %p %m
There are two special symbols used that will get replaced before execution.

TEST_RUNNER is the name of the class or executable that will be used when the Test button is clicked.
default: fit.FitServer
If you're running tests in Java you probably don't want to change this.

PATH_SEPARATOR is the charater that is used to separate all the path elements in the calculated path.
default: system dependant.... either ; or :