We address the problem of dealing with the heterogeneity of access devices. The problem we are facing is that of a, possibly mobile, user that wants to download and execute an application from a remote server. The user?s hosting device can be of various kinds PCs, PDAs, cellular phones, communicators, etc. with specific hardware and software capabilities. The problem is then to be able to decide whether the user?s current device characteristics are compatible with the application requirements in order to prevent execution failures. In the negative case we would like to be able to identify the reasons that determined the uncompatibility and perform an adaptation of the application so that it can match the user?s device capabilities.