To easily discover the mismatching of programs in an early stage by detecting various problems due to the use of an already existing user defining module.

This information processor is provided with an environment defining part for defining environment definition data in an performing environment with respect to a program to be developed, a check part for verifying the virtual performing state of the development program in the performing environment based on the environment definition data, a display information preparing part for preparing display information for visually displaying the virtual performing state, a display device for displaying the display information to a user, an interface part formed on the display screen of the display device for allowing the user to perform an operation to change the visually displayed virtual performing state on the display screen, an performance object generating part for outputting the development program in configurations performable under the performing environment, and a user defining module registering part for defining information related with a user defining module to be used by the development program.