Measures are described which provide a framework for the registration and selection of applications and/or services. A registration procedure comprises receiving an indication of one or more services that an application is configured to perform; receiving an indication of one or more characteristics of data objects in respect of which the indicated service is configured to be performed; and storing, in the data store, data entries indicating each of the services and associated characteristics. A selection procedure comprises determining one or more data objects for selection; identifying, one or more services that may be performed in relation to at least one of the one or more data objects; and displaying one or more selectable elements corresponding to the identified services and data objects.