We propose D-uMiddle, a middleware framework that enables devices and sensor nodes in different smart spaces to interact with one another across the Internet. The development of pervasive systems has created smart spaces, where embedded sensors detect user contexts, and computational engines assists user activities. Even though there exists middleware platforms aiming at interoperability among devices, those smart spaces form isolated islands of devices with no uniform protocol for interoperability across smart spaces. This void makes it difficult to develop distributed pervasive computing applications integrating devices and sensor nodes in multiple different smart spaces. D-uMiddle is a framework for achieving such interoperability, and serves as a powerful platform for creating distributed pervasive computing applications that can integrate devices across smart spaces.