ON

(Default) Specifies that Visual FoxPro recompile the source program before it executes if it is more current than its compiled object program. This option ensures that the most current version of a program is executed.

OFF

Specifies that Visual FoxPro not compare the source and compiled versions of the program. If SET DEVELOPMENT is set to OFF, you might not always be executing the most current version of a program.

SET DEVELOPMENT needs to be set to ON when programs are modified outside of Visual FoxPro. Using an external editor may require you to issue CLEAR PROGRAM before you execute the modified program. For more information, see CLEAR PROGRAM. Use SET DEVELOPMENT OFF for optimum performance.

SET DEVELOPMENT also determines whether the Trace window is opened when an error occurs within a Form that is running. If SET DEVELOPMENT is ON, the Trace window is opened with the program line that caused the error selected. If SET DEVELOPMENT is OFF, the Trace window is not opened when an error occurs in a Form.