TPO++: An object-oriented message-passing library in C++. TPO++ is an object-oriented message passing library intended for parallel programming. It is based on the Message Passing Interface (MPI) but allows to transmit objects and data structures of the standard template library. Message-passing is a well known approach for parallelizing programs. The widely used standard MPI also defines C++ bindings. Nevertheless, there is a lack of integration of object-oriented concepts. TPO++ tries to close this gap.