The present invention is to provide a system, a method, and a program for distributing a container image that do not need to previously prepare the execution environment for individual terminals and external systems on the execution of a predetermined application on a terminal and an external system. The system for distributing a container image registers a container image that includes an application and a program group for the execution environment of the application; receives start instruction from a user to start the registered container image; receives selection of a platform that distributes the container image instructed to be started, from the user; and distributes the container image instructed to be started to the selected platform.