Information processing apparatus, information processing system, and controlling method of information processing apparatus

There is provided an information processing apparatus in which a great number of users can use thin clients, and in which various services such as simultaneous picture distribution are realized in an integrated manner, an information processing system, and a controlling method of the information processing apparatus. The apparatus capable of executing plural OSs includes image transmitting devices having: a GPU for receiving a drawing instruction signal of a screen output from the OS and generating an image signal of a display screen; and a communicator for transmitting the image signal of the display screen to a terminal that operates as a thin client. The devices compressively code the image signal to a digital motion picture by a coding unit as necessary. Then, the devices transmit the coded signal from the communicator. The apparatus dynamically assigns the devices to the OSs corresponding to the respective terminals via VMM.