Method for simultaneously managing a plurality of manipulable graphic objects (0#1-0#7) coming from multiple multimedia sources, the multimedia sources being executed by different operating systems, each of said manipulable graphic objects being displayed individually according to a common graphic composition on a touchscreen having a control surface for the input of touch controls by a user, wherein: the content of a plurality of source image memories (11, 21, 31) for each respective multimedia source is provided to a final composition unit, each source image memory of each respective multimedia source storing a graphic plane of a single graphic object to display created by the respective multimedia source, said graphic plane comprising information relating to the colour and transparency of said graphic object for each pixel of said touchscreen; said graphic planes of each source image memory are combined in the final composition unit according to a predefined superposition order so as to create said common graphic composition according to which said manipulable graphic objects are displayed on said touchscreen, a touch control applied to an area of the screen, intended to manipulate at least one manipulable graphic object displayed on said area of the screen, is received, at the final composition unit, the multimedia source from where said manipulated graphic object comes is identified on the basis of the order of superposition of the graphic planes and the transparency information provided by said graphic planes of said plurality of source image memories for said area of the screen, the identification of said multimedia source from where said manipulated graphic object comes consisting in using the transparency information of each of said graphic planes, taken successively according to said superposition order, up until determining the graphic plane for which the transparency information is different to zero for said area of the screen in question, said touch control is transmitted to said identified multimedia source which will update its source image memory on the basis of said received touch control, in the frame of reference of said manipulated graphic object, touch coordinates associated with said touch control applied to the screen are calculated on the basis of the touch coordinates associated with said touch control in the frame of reference of said screen and said touch coordinates calculated in this way are transmitted to said identified multimedia source, and the content of said updated source image memory is provided to said final composition unit so as to create a new common graphic composition which takes into account the manipulation of said manipulated graphic object, for display on the screen. the content of a plurality of source image memories (11, 21, 31) for each respective multimedia source is provided to a final composition unit, each source image memory of each respective multimedia source storing a graphic plane of a single graphic object to display created by the respective multimedia source, said graphic plane comprising information relating to the colour and transparency of said graphic object for each pixel of said touchscreen; said graphic planes of each source image memory are combined in the final composition unit according to a predefined superposition order so as to create said common graphic composition according to which said manipulable graphic objects are displayed on said touchscreen, a touch control applied to an area of the screen, intended to manipulate at least one manipulable graphic object displayed on said area of the screen, is received, at the final composition unit, the multimedia source from where said manipulated graphic object comes is identified on the basis of the order of superposition of the graphic planes and the transparency information provided by said graphic planes of said plurality of source image memories for said area of the screen, the identification of said multimedia source from where said manipulated graphic object comes consisting in using the transparency information of each of said graphic planes, taken successively according to said superposition order, up until determining the graphic plane for which the transparency information is different to zero for said area of the screen in question, said touch control is transmitted to said identified multimedia source which will update its source image memory on the basis of said received touch control, in the frame of reference of said manipulated graphic object, touch coordinates associated with said touch control applied to the screen are calculated on the basis of the touch coordinates associated with said touch control in the frame of reference of said screen and said touch coordinates calculated in this way are transmitted to said identified multimedia source, and the content of said updated source image memory is provided to said final composition unit so as to create a new common graphic composition which takes into account the manipulation of said manipulated graphic object, for display on the screen.