In recent years, various mobile middleware systems have been developed that build on top of the protocol stacks provided by the underlying network operating systems, to offer a set of higher-level services. Common services provided include remote procedure calls, data sharing, or service discovery. With the number of mobile devices, such as PDAs, mobile telephones, or smart phones increasing, as well as the impeding flourishing of embedded and wearable computing, the rôle of middleware in offering services that hide the complexity in the underlying environment is at the same time important and complex. The mobile environment is becoming highly dynamic, with very heterogeneous devices, in terms of both hardware and software, forming short lived ad hoc networks. Here, it is argued that the provision of static services cannot tackle the peculiarities of this environment. Logical mobility is presented as a technique for dynamic adaptation, a specification of a framework that offers its flexible use is detailed, and a number of dynamic middleware services is presented, which can intelligently be acquired by a device at run-time.