The conventional approach for building pervasive environments relies on middleware to integrate different systems. Instead, we have built a system that can deal with these environments by exporting system resources through distributed virtual Jile systems. This requires no middleware, simplijies interoperation, and permits applying general purpose tools to any system resource. A constraintbased jile system import mechanism allows the system to adapt to changes in the environment and permits users to customize the environment and tailor adaptation according to their needs. The system has been in use for over a year to carry out our daily work and is underlying the smart space that we built for our department.