Editorial introduction: second part of the special issue on product forms, stochastic matching, and redundancy.

This document is an editorial introduction to the second part of a special issue of the journal Queueing Systems. The special issue focuses on product forms, stochastic matching, and redundancy models in the analysis of queueing systems. The papers in this collection explore various aspects of matching queues and redundancy systems, including fluid approximation, heavy traffic limits, and different scheduling policies. The goal of the special issue is to highlight the connections between these models and their product-form stationary distributions, and to inspire new directions for future research. [Extracted from the article]