An operating system built from the bootloader up
Forest OS is a hobby operating system developed in the open. Everything in it — the bootloader, the kernel, the cross-compiler toolchain and the supporting libraries — lives in a single public repository under the GNU GPL v3.
It is written for people who want to read an OS rather than just run one. The code is small enough to follow end to end, and the repository includes notes on how the pieces fit together.
Get Forest OS Browse the source on GitHub
What's in the box
- Fern — the kernel. Memory management, tasks, VFS, and the session manager that brings up your shell.
- foreboots — the bootloader, covering both raw MBR/BIOS and UEFI.
- forestlibs — a POSIX-oriented C library that the system ABI targets.
- forestos-toolchain — the
i686-forestosandx86_64-forestoscross-compilers, built from source. - userspace — the applications, including
forest-shellwith pipes, redirection, job control and history.
The system as a whole is Forest-OS, codename ALDER. The kernel on its own is Fern.
Free software, no strings
Forest OS is licensed under the GPL v3. You can run it, read it, change it and share your changes. There is no paid edition, no telemetry and no account to create. This website is open source too — see the Source page.
It's written by Bluethefox and hosted by Enclica. If you'd like to support the work, there's a PayPal link — optional, and it changes nothing about what you get.
Early days. Forest OS is under active development and is not a daily-driver system. Run it in a virtual machine such as QEMU. Do not install it on hardware you care about.