We present ABAplus, a system that implements reasoning
with the argumentation formalism ABA+. ABA+ is a structured argumentation
formalism that extends Assumption-Based Argumentation
(ABA) with preferences and accounts for preferences via attack reversal.
ABA+ also admits as instance Preference-based Argumentation which
accounts for preferences by reversing attacks in abstract argumentation
(AA). ABAplus readily implements attack reversal in both AA and ABAstyle
structured argumentation. ABAplus affords computation, visualisation
and comparison of extensions under five argumentation semantics.
It is available both as a stand-alone system and as a web application.