Mobile computing creates the need for applications to be adaptable according to the user s context. Specific user demands as well as changes in the computational context the mobile applications require clients to be able to adapt dynamically to suit the new scenario of execution. These adjustments should be appropriate and should maintain the quality of service avoiding failures or preventing degradation of application performance. This thesis proposes an extension of Kaluana middleware which provides a mechanism for selection of components for adaptive applications based on the notion of reconfigurations contracts. This selection is done also based on the notion of equivalence between their public interfaces and should consider the execution restrictions of the candidate components to be used in the adaptation in accord to the device s execution context to be used to evaluate the candidate components to the instantiation. This selection aims to maintain the compatibility of new components with the components already used as well as the execution context, i.e. the current status of the device s resources. Due to the notion of equivalence between the interface specifications of components, the application should be able to request a component through the interface of the requested service, avoiding the need to know the component s name or any other specific feature that creates a tie with the given implementation.