IDL Executive Commands

Most users quickly learn about the .compile and perhaps the .reset_session executive commands, but there are many more available:

From page 10 of the IDL Quick Reference Manual:

Executive Commands

.COMPILE - Compiles programs without running.
.CONTINUE - Continues execution of a stopped program.
.EDIT - Opens files in editor windows of the IDL Workbench.
.FULL_RESET_SESSION - Does everything .RESET_SESSION does, plus additional reset tasks such as unloading sharable libraries.
.GO - Executes a previously compiled $MAIN$ program.
.OUT - Continues execution until the current routine returns.
.RESET_SESSION - Resets much of the state of an IDL session without requiring the user to exit and restart the IDL session.
.RETURN - Continues execution until RETURN statement.
.RNEW - Erases $MAIN$ program variables and then executes .RUN.
.RUN - Compiles and executes IDL commands from files or keyboard.
.SKIP - Skips over the next n statements and then single steps.
.STEP - Executes one or n statements from the current position.
.STEPOVER - Executes a single statement if the statement does not call a routine.
.TRACE - Similar to .CONTINUE, but displays each line of code before execution.

More information on each command can be found in the IDL Reference Guide starting on page 47 and at the IDL Reference Guide web site published by NASA.