When dealing with complex systems, information is very often fragmented across many different models expressed within a variety of (modeling) languages. To provide the relevant information in an appropriate way to different kinds of stakeholders, (parts of) such models have to be combined and potentially revamped by focusing on concerns of particular interest for them. Thus, mechanisms to define and compute views over models are highly needed. Several approaches have already been proposed to provide (semi)automated support for dealing with such model views. This paper provides a detailed overview of the current state of the art in this area. To achieve this, we relied on our own experiences of designing and applying such solutions in order to conduct a literature review on this topic. As a result, we discuss the main capabilities of existing approaches and propose a corresponding research agenda. We notably contribute a feature model describing what we believe to be the most important characteristics of the support for views on models. We expect this work to be helpful to both current and potential future users and developers of model view techniques, as well as to any person generally interested in model-based software and systems engineering.