A software program for creating features for use with a plurality of media objects in a sequence. The program comprises a feature component specifying a feature having parameters affecting at least one variable aspect of the feature. An indicator component identifies a position of the specified feature relative to the media objects in the sequence. The program comprises a sequence generator for modifying the specified feature by varying its parameters of the specified feature as a function of the position of the specified feature relative to the media objects and/or relative to other features in the sequence. The sequence generator also modifies the specified feature by varying its parameters of the feature as a function of the content of the media objects around it or to which it has been applied. A rendering component renders the specified feature according to the varied parameters at the identified position.