This book brings together the content that has been created over the past years in the context of AbstractSwarm. AbstractSwarm is a Multi-Agent Modeling and Simulation System for Logistics (and similar) scenarios. The main idea of the system is the strict separation of the scenario modeling ("what to do") and the agent behavior ("how to do it"). This results in a system where agents can in principle be put into arbitrary scenarios for improving the underlying processes. As a consequence, generic agent implementations are needed to cooperate in different kinds of scenarios. This small book is planned on the occasion of the 20th anniversary of AbstractSwarm for 2026 by the organization committee of the AbstractSwarm Multi-Agent Logistics Competition. After providing some historical notes on the AbstractSwarm modeling and simulation system in Part I, Part II introduces technical aspects of the AbstractSwarm system. Part III concerns the AbstractSwarm Multi-Agent Competition, a competition held for four years (three of them with submissions) for finding the most adaptive agent implementations in the context of the AbstractSwarm system. Finally, Part IV gives an outlook on future work in the context of the AbstractSwarm system.