(eng): Studying logics via semantics is a well-established and very active branch of mathematical logic, with many applications, in computer science and elsewhere. The area is characterized by results, tool and techniques stemming from various fields, including universal algebra, topology, category theory, order, and model theory. The programme of the conference TACL 2017 will focus on three interconnecting mathematical themes central to the semantical study of logics and their applications: algebraic, categorical, and topological methods. This is the eight conference in the series Topology, Algebra and Categories in Logic (TACL, formerly TANCL). Earlier installments of this conference have been organized in Tbilisi (2003), Barcelona (2005), Oxford (2007), Amsterdam (2009), Marseille (2011), Nashville (2013) and Ischia (2015).