1. A computer system comprising: at least one memory storing instructions; and at least one processor configured to execute the instructions which, when executed, implement a user interface (UI) designer client, a client engine, a UI runtime server client, a repository and a customized view engine, wherein: the user interface designer client is arranged and configured to run on a first client device on a client side of a network to enable creation of UI models; the client engine is arranged and configured to run on a second client device on the client side of the network as a plug in application to a browser application without using a Java stack to initiate requests for one or more of the UI models and to initiate requests for one or more host-based applications, receive the UI models in response to the requests and interpret and render the UI models at runtime; the UI runtime server client is located on a server on the server side of the network and is arranged and configured to interface with the client engine to receive and process the requests for the UI models from the client engine and to receive and process the requests for the host-based applications including a common output for the host-based applications; and the repository is located on the server on the server side of the network and is arranged and configured to: interface with the UI designer client and store the UI models as created using the UI designer client and to store the host-based applications, and interface with the UI runtime server client to deliver requested UI models to the UI runtime server client for interpretation and rendering by the client engine, wherein the client engine further comprises the customized view engine that is configured to provide a customized output of the host-based applications to a particular user, wherein the customized output is different from the common output of the host-based applications received from the UI runtime server.