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Welcome to The Fiwix Project

Fiwix v1.0 will be released on
23 April 2018!

Current Version:
0.9.2 (aka 1.0.0-RC)
Working on:
- sys_select()
Other Projects:

What is Fiwix?

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GNU/Fiwix 0.7.1 (video)
Fiwix is an operating system kernel written from scratch, based on the UNIX architecture and fully focused on being POSIX compatible. It is designed and developed mainly as a hobby OS and, since it serves also for educational purposes, the kernel code is kept as simple as possible for the benefit of readers or students. It runs on the 32-bit x86 hardware platform and is compatible with a good base of existing GNU applications.

The Linux kernel is currently too big for a student of computer science to be able to understand quickly its internal structure and how it works, and tomorrow it will be even bigger than it is today. In contrast the Fiwix kernel, due to its minimal structure, can be the entry-level kernel and can therefore be more suitable for education. This project should be useful for students of computer science and new OS enthusiasts who might want to know more about the internal operation of a real UNIX-like operating system.

Do not think of GNU/Fiwix as a new UNIX flavor with its own system utilities, libraries, compilers, etc. Think about GNU/Fiwix as a new UNIX-like kernel that takes advantage of the existing GNU applications.

It is based on the monolithic kernel design and it is written entirely in C language, leaving only for the Assembler the small needed parts.

The development team is one person: me.


The project targets the following goals.
  • To create a UNIX-like kernel as an old personal challenge.
  • To provide a simple and a clean source code for educational purposes.
  • To learn about the exciting world of kernel internals.
  • To conform with open standards as much as possible.
  • To enjoy my life with a little bit of kernel hacking. ;-)

Latest news



The Fiwix kernel is expected to be publicly available under an open source license when it reaches the 1.0 version (self-hosting).

Fiwix v1.0.0 is expected to be released on 23 April 2018.