A peripheral apparatus which can communicate with a server via a network has: user interface means for operating the peripheral apparatus; communicating means for performing a log-in to the server; information obtaining means for obtaining operating environment information of the log-in user from operating environment managing means of each user of the server when the user is authenticated by the server; user interface constructing means for constructing a user interface such as an operating picture plane or the like in accordance with the operating environment information of the user; program downloading means for, when execution of a predetermined program held by program information managing means of each user on the server is instructed by the user interface means, downloading the program whose execution has been instructed from the server; data managing means for holding the downloaded program; and program executing means for executing the downloaded program. A server which communicates with the peripheral apparatus and a system including those apparatuses are also disclosed.