A process-time diagram showing the execution his tory of individual processes and the interactions between processes can be a very useful tool in under standing the behavior of a distributed or concurrent application. Managing the size of these visualizations via suitable abstraction facilities is essential for long running and complex applications. This paper de scribes Poet, a tool that collects and visualizes event traces from applications running in several different target environments, such as OSF DCE, ABC++ SR, and PVM. To manage the complexity of the resulting visualizations for non-trivial executions, Poet supports abstraction facilities in both the process and time dimensions. These abstraction facilities enable Poet to visualize distributed executions on a number of abstraction levels. To achieve target-system independence, Poet makes as few assumptions as possible about characteristics that must be possessed by all target environments. Information describing each target environment is placed in configuration files, al lowing a single set of Poet executables to be used for all target environments.