Report on the "The Future of the Shell" Panel at HotOS 2021.

This document summarizes the challenges and possible research directions around the shell and its ecosystem, collected during and after the HotOS21 Panel on the future of the shell. The goal is to create a snapshot of what a number of researchers from various disciplines -- connected to the shell to varying degrees -- think about its future. We hope that this document will serve as a reference for future research on the shell and its ecosystem.