The Mobile Computing has emerged as a new field, distinct from conventional distributed computing by its focus on mobility and its consequence. The physical and logical mobility needs of applications with new requirements: built-in mobility, adaptability and flexibility. Providing a system architecture that simplifies the task of implementing the mobile applications with adaptive behavior is the objective of the ongoing ISAM Project. In order to achieve its goal, ISAM uses, as strategies, an integrated environment that: (a) provides a programming paradigm and its execution environment; (b) treats of adaptation process through multilevel collaborative model, in which both the system and the application contribute for that. In this paper, we present the ISAM architecture and introduce the relative issues to the treatment of adaptive mobile applications.