 Results on combinations of logics may quickly become too technical when we turn to the combination of higher-order, modal, relevance logics or non-truth-functional logics, and thus refinements of the notion of algebraic fibring such as modulated fibring (see C. Sernadas et al. 2002b) or cryptofibring (see Caleiro and Ramos 2007) may be necessary to solve, for example, some collapsing problems within combinations of logics (see  section 5).  This naturally leads to the use of category theory as a universal language and as a tool to deal with such problems. But the fact is that combinations of logics do not necessarily depend upon any highly technical methodology, and even some relatively simple examples can be really expressive. There is a recognized intersection and interaction between Philosophy and theoretical Computer Science, and techniques for combining logics are also revealed to be very apt tools for handling and thus better understanding Kripke models. Having been introduced in the domain of Philosophical Logic, Kripke models are essential in Computer Science and Artificial Intelligence as semantic structures for logics of belief, knowledge, temporal logics, logics for actions, etc. Knowledge representation and reasoning may require combining several reasoning formalisms, including combinations of temporal reasoning, reasoning in description logic, reasoning about space and distance, and so on. Logics, combining temporal and modal dimensions, are also becoming a relevant tool in agent-oriented programming languages. Other applications of combinations of logics include software specification, knowledge representation, architectures for intelligent computing and quantum computing, security protocols and authentication, secure computation and zero-knowledge proof systems, besides their connections to formal ethics and game semantics.