The aim of my paper is to investigate how major semantic theories are used in various application areas. The viewpoint I take in the present paper is that of the pragmatist: I approach and evaluate the evolving theories on the basis of how useful they are in terms of their contribution to so-called “real-world” applications, “[f[or theoretical proposals in science are judged ‘pragmatically’, by their theoretical fruitfulness” (Burge, 3). For the purposes of effective comparison, I structured my paper according to the following strategy. First, I align the prominent semantic theories, along with their outstanding representatives, the sub-theories that make up or closely accompany the main line of thought, and the derivative theories. Following this outline, the second part of the paper gives an account of ontologies, which are marginal between semantic theories and applications. Then I present the numerous areas where semantics can play a role. For every application, I examine its importance (reflecting on my subjective view) and the underlying semantic framework. Finally, I revisit the semantic theories in light of their applicability.