What is plan9-hostfs?

Plan 9 HostFS lets you run an old operating system called Plan 9 inside a virtual machine using QEMU, with a normal folder on your own computer acting as that operating system's file system. It is based on an earlier project by Russ Cox that combined a bootable Plan 9 tree with QEMU and a tool called u9fs, which shares files between the host computer and the guest system. This fork keeps that same idea of editing files directly from either side, host or guest, but separates the project's own files and tools from the folder that actually gets shared with Plan 9. To use it, you need a Linux computer, or Windows through WSL, since Windows file permissions cannot represent what the Plan 9 files expect. You also need QEMU installed, a build tool called make, and a C compiler, since the launcher builds a small helper program called u9fs automatically the first time you run it. After cloning the repository, a single launcher script starts the virtual machine, where you pick a screen resolution and then choose a boot option to start the shared filesystem guest. There is also a standalone mode that sets up one authenticated identity, named glenda, with a password you choose on first run. This mode stores its state files outside the project folder and is meant for one person working locally, not as a login server for multiple people. A separate program called drawterm, connecting over specific network addresses, lets you open a terminal session into that running Plan 9 instance, and more than one drawterm window can connect to the same instance at once. A simpler mini mode boots a small, self-contained version of Plan 9 that does not touch your shared host folder at all, useful for a quick look without setting anything else up. This project suits people curious about retro or experimental computing, since Plan 9 is a historic research operating system rather than a tool for everyday production work. The README documents licensing details that mirror the original Plan 9 files, and it is explicit that this fork's own changes and decisions should not be credited back to the original author.