: This paper briefly summarizes the work towards the final version of ‘Distributed Transaction Processing’ (OSI TP). Several well-known optimizations of the presumed abort protocol are introduced: dynamic flow of READY-messages, a one-phase protocol, a read-only extension. Moreover, some useful extensions such as containment of heuristic decisions and reporting of the completion status of a transaction are presented. The requirements and the functionality are discussed especially from the user's point of view. Finally, the evolving requirements for distributed transaction processing are discussed given the increasing number of applications on the Internet (Electronic Commerce).