Information presentation desktop applications such as media players, digital signage players are heavily encountered by us in our daily life. However current presentation oriented desktop application architectures are not flexible and less efficient in presenting a variety of information. Desktop applications rely on embedded files and the contents they present are bound to presentation layout. This paper presents "Media Content Expression Architecture" (MEXARC), a solution for the aforementioned problem. MEXARC uses XML based declarative graphical user interface languages for creating the presentations which provides efficient handling of information compared to legacy presentational architectures. Two software prototypes named Infoshare and TelescopeVisualizer were developed based on MEXARC to evaluate its applicability in digital signage systems and information visualizers. Evaluation of MEXARC applications were done considering the aspect of scalability. It was observed that Infoshare web service and Telescope server are scalable in terms of hardware resources. Paper contributes to the area of presentational desktop applications by introducing a novel, scalable and generic smart client software architecture that can be applied in different presentational scenarios. We envision future applications of MEXARC in E-learning, Online Gaming and Television. The paper describes the MEXARC architecture and how it has been applied for the two software prototypes.