We present Panelrama, a web-based framework for the construction of applications using distributed user interfaces (DUIs). Our implementation provides developers with low migration costs through built-in mechanisms for the synchronization of a UI state, requiring minimal changes to existing languages. Additionally, we describe a solution to categorize device characteristics and dynamically change UI allocation to best-fit devices. We illustrate the use of Panelrama through three sample applications which demonstrate its support for known interaction methods, we also present the results of a developer study, which validates our belief that cross-device application experiences can be easily implemented using our framework.