The Fregean notion of a proposition as a mind-independent abstract object that has truth conditions essentially is a central notion both in linguistic semantics and in contemporary philosophy of language. Recently, a number of philosophers of language have put forward serious criticisms against this notion, however, and have proposed instead act-based conceptions of propositional content, tying the representational status of propositions to the intentionality of agents (Jubien, Hanks, Soames, among others). The course will discuss the motivations and the different developments of the act-based approach to propositional content with their actual and potential semantic applications. It will most importantly present a particular version of the act-based approach based on the notion of a (nonenduring) product of an act, an agent- and mind-dependent ‘abstract artifact’ (Thomasson). It will develop various novel formal semantic applications of that approach, in particular to the semantics of different sorts of clausal complements and the semantics of quotation.