The Tableau Workbench (TWB) is a generic framework for building automated theorem provers for arbitrary propositional logics. The TWB has a small core that defines its general architecture, some extra machinery to specify tableau-based provers and an abstraction language for expressing tableau rules. This language allows users to “cut and paste” tableau rules from textbooks and to specify a search strategy for applying those rules in a systematic manner. A new logic module defined by a user is translated and compiled with the proof engine to produce a specialized theorem prover for that logic. The TWB provides various hooks for implementing blocking techniques using histories and variables, as well as hooks for utilising/defining optimisation techniques. We describe the latest version of the TWB which has changed substantially since our system description in TABLEAUX 2003.