1 ) A method for reusing an application object for use with an application program, comprising: a reference detection step of detecting that said application program ends referring to said application object; an update detection step of detecting that said application object is updated by said application program; a reuse decision step of deciding to reuse said application object in response to detecting no update of said application object; and a reusing step of making said application object reusable in response to an end of referring to said object and a decision to reuse said application object.