  In this thesis my papers hep-th/0104190, hep-th/0310214, hep-th/0405072 and
hep-th/0406065 are put into context. The thesis is mainly focused on
noncommutative field theory and string theory, so results in the papers that
are not related to this main theme are not discussed in detail. The thesis is
almost selfcontained and in particular the first chapter might be useful as an
introduction to non(anti)commutative geometry and its relation to superstring
theory for beginners in the field. The following chapters also contain some
review material that is not present in the papers, concerning some selected
topics in the theory of integrable models and a discussion of the main features
of the pure spinor approach to superstrings. The thesis was handed in in
October 2004, so the bibliography only refers to work appeared on the web
before this date.
