System for creating and deploying applications on a plurality of types of client device, comprising a plurality of client devices of various types each hosting at least one client application and a server in communication with said plurality of client devices hosting at least one main application, said main application comprising at least a logic part, a graphical part and an interface selector, said graphical part comprising a virtual module for storing a plurality of user interfaces referred to as panel spaces and a virtual module for managing the graphical interfaces referred to as a virtual space, said interface selector being configured so as to make a type of user interface correspond to each type of client device, said virtual space: - comprises at least one data communication module, referred to as namespace, said namespace comprising at least one interaction object such as a filler field and/or a table and/or an action; - is configured to allow communication between the logic part of the main application and the graphical part; and - is configured to permanently store the state of activation of the main application following modifications ordered by at least one of the client applications, the system being configured so that each of the user interfaces comprises a plurality of panels and each of the panels comprises at least one widget, and wherein the at least one widget of each panel is associated with one of the at least one interaction object of at least one namespace in order to receive and send data to said associated namespace by means of the activation of the widgets and/or of the interaction objects, the client applications preferably being configured to display only one panel at a time, each of the client devices in the plurality of client devices being configured to be connected to a single user session, the system being configured so as to perform at least the following steps in response to an activation of the at least one client application, these steps being performed by at least one microprocessor: - receiving from the client device through the interface selector data corresponding to the activation of a widget present on the panel displayed on the client device, - transmitting said data with a status of use data to the corresponding panel of the panel space, - activating the widget of the corresponding panel in the panel space, - transmitting said use data from said panel to the associated namespace in the virtual space, - activating the interaction object of the namespace corresponding to said widget of the panel space, - sending the use data from the virtual space, in particular from the namespace, to the logic part, in particular to the main application, - processing the use data by the logic part and changing said use data from a status of use data to a status of processed data, - sending the processed data to a namespace identical to or different from the one that transmitted the use data from the main application, in particular from the logic part, to an interaction object, - transmitting the processed data from the virtual space and in particular from the interaction object of a namespace to at least one corresponding widget in the panel space, transmitting the processed data from the at least one widget of the panel space to the client applications of the plurality of client devices, each modification on one of the user interfaces consequently affecting the other user interfaces displayed on the various client devices. - comprises at least one data communication module, referred to as namespace, said namespace comprising at least one interaction object such as a filler field and/or a table and/or an action; - is configured to allow communication between the logic part of the main application and the graphical part; and - is configured to permanently store the state of activation of the main application following modifications ordered by at least one of the client applications, - receiving from the client device through the interface selector data corresponding to the activation of a widget present on the panel displayed on the client device, - transmitting said data with a status of use data to the corresponding panel of the panel space, - activating the widget of the corresponding panel in the panel space, - transmitting said use data from said panel to the associated namespace in the virtual space, - activating the interaction object of the namespace corresponding to said widget of the panel space, - sending the use data from the virtual space, in particular from the namespace, to the logic part, in particular to the main application, - processing the use data by the logic part and changing said use data from a status of use data to a status of processed data, - sending the processed data to a namespace identical to or different from the one that transmitted the use data from the main application, in particular from the logic part, to an interaction object, - transmitting the processed data from the virtual space and in particular from the interaction object of a namespace to at least one corresponding widget in the panel space, transmitting the processed data from the at least one widget of the panel space to the client applications of the plurality of client devices, each modification on one of the user interfaces consequently affecting the other user interfaces displayed on the various client devices.