FAQ

This page covers questions and answers for newcomers and end-users.

What is Redox?

Redox is a microkernel-based, complete, fully-functioning and general-purpose operating system created in 2015, with a focus on safety, freedom, reliability, correctness, and pragmatism. Wherever possible, the system components are written in Rust and run in user-space.

It aims to be a complete alternative to Linux and BSD.

Current status

Redox is alpha/beta quality software, because we implement new features while fixing the bugs.

Because of this, it’s not ready for daily usage yet. Feel free to test the system until its maturity and don’t store your sensitive data without a proper backup.

The 1.0 version will be released once all system APIs are considered stable.

What does Redox mean?

Redox is the chemical reaction (reduction–oxidation) that creates rust. As Redox is an operating system written in Rust, it makes sense.

It sounds like Minix and Linux too.

What features does Redox have?

Microkernel benefits

You can modify/change many system components without a system restart, similar to but safer than some kernel modules and livepatching.

Most system components run in user-space on a microkernel system. Because of this, bugs in most system components won’t crash the system/kernel.

A mature microkernel changes very little (except for bug fixes), so you won’t need to restart your system very often to update it.

Since most of the system components are in userspace, they can be replaced on-the-fly, reducing downtime of servers a lot.

Most of the system components run in userspace, simplifying the testing and debugging.

You can read more about the above benefits on this page.

Rust benefits

The restrictive syntax and compiler requirements to build the code reduce the probability of bugs a lot.

The Rust compiler helps the programmer to avoid memory errors and race conditions, which reduces the probability of data corruption bugs.

The microkernel design written in Rust protects against memory defects that one might see in software written in C/C++.

By isolating the system components from the kernel, the attack surface is very limited.

As the kernel is small, it uses less memory to do its work. The limited kernel code size helps us work towards a bug-free status (KISS).

Rust’s safe and fast language design, combined with the small kernel code size, helps ensure a reliable, performant and easy to maintain core.

The C/C++ support for thread-safety is quite fragile. As such, it is very easy to write a program that looks safe to run across multiple threads, but which introduces subtle bugs or security holes. If one thread accesses a piece of state at the same time that another thread is changing it, the whole program can exhibit some truly confusing and bizarre bugs.

You can see this example of a serious class of security bugs that thread-safety fixes.

In Rust, this kind of bug is easy to avoid: the same type system that keeps us from writing memory unsafety prevents us from writing dangerous concurrent access patterns

Drivers written in Rust are likely to have fewer bugs and are therefore more stable and secure.

Other benefits

Redox uses RedoxFS as the default filesystem. It supports similar features as ZFS with a written-in-Rust implementation.

Expect high performance and data safety (copy-on-write, data integrity, volumes, snapshots, hardened against data loss).

Comparison with other operating systems

You can see how Redox is compared to Linux, FreeBSD and Plan 9 on these pages:

What is the purpose of Redox?

The main goal of Redox is to be a general-purpose OS, while maintaining security, stability and correctness.

Redox aims to be an alternative to existing Unix systems (Linux/BSD), with the ability to run most Unix programs with only recompilation or minimal modifications.

What I can do with Redox?

As a general-purpose operating system, you will be able to do almost any task on most devices with high performance and security.

Redox is still under development, so our list of supported applications is currently limited, but growing.

What is an Unix-like OS?

Any OS compatible with the Single Unix Specification and POSIX. You can expect a shell, the “Everything is a File” concept, multitasking and multiuser support.

Unix was a highly influential multitasking system and impacted the design choices of most modern systems.

How Redox was influenced by other systems?

Plan 9

This Bell Labs OS brings the concept of “Everything is a File” to the highest level, doing all the system communication from the filesystem.

Minix

The most influential Unix-like system with a microkernel. It has advanced features such as system modularity, kernel panic resistence, driver reincarnation, protection against bad drivers and secure interfaces for process comunication.

Redox is largely influenced by Minix - it has a similar architecture but with a feature set written in Rust.

seL4

The most performant and simplest microkernel of the world.

Redox follow the same principle, trying to make the kernel-space small as possible (moving components to user-space and reducing the number of system calls, passing the complexity to user-space) and keeping the overall performance good (reducing the context switch cost).

BSD

This Unix family included several improvements on Unix systems and the open-source variants of BSD added many improvements to the original system (like Linux did).

Linux

The most advanced monolithic kernel and biggest open-source project of the world. It brought several improvements and optimizations to the Unix-like world.

Redox tries to implement the Linux performance improvements in a microkernel design.

What is a microkernel?

A microkernel is the near-minimum amount of software that can provide the mechanisms needed to implement an operating system, which runs on the highest privilege of the processor.

This approach to OS design brings more stability and security, with a small cost on performance.

You can read more about it here.

What programs can Redox run?

Redox is designed to be source-compatible with most Unix, Linux and POSIX-compliant applications, only requiring compilation.

Currently, most GUI applications require porting, as we don’t support X11 or Wayland yet.

Some important software that Redox supports:

You can see all Redox components and ported programs here.

How to install programs on Redox?

Redox has a package manager similar to apt (Debian) and pkg (FreeBSD), you can see how to use it on this page.

Which are the Redox variants?

Redox has some variants for a group of tasks, take a look at them below:

Which devices does Redox support?

There are billions of devices with hundreds of models and architectures in the world. We try to write drivers for the most used devices to support more people. Support depends on the specific hardware, since some drivers are device-specific and others are architecture-specific.

Have a look at HARDWARE.md to see all tested computers.

CPU

Hardware Interfaces

(USB soon)

Video

(Intel/AMD and others in the future)

Sound

(Sound Blaster soon)

Storage

(USB soon)

Input

Internet

(Wi-Fi and Atheros ethernet soon)

I have a low-end computer, would Redox work on it?

A CPU is the most complex machine of the world: even the oldest processors are powerful for some tasks but not for others.

The main problem with old computers is the amount of RAM available (they were sold in a era where RAM chips were expensive) and the lack of SSE/AVX extensions (programs use them to speed up the algorithms). Because of this some modern programs may not work or require a lot of RAM to perform complex tasks.

Redox itself will work normally if the processor architecture is supported by the system, but the performance and stability may vary per program.

Which virtual machines does Redox have integration with?

In the future the microkernel could act as a hypervisor, similar to Xen.

A hypervisor is a program providing the ability to run multiple isolated operating systems instances simultaneously.

How do I build Redox?

Read the following pages:

How to troubleshoot your build in case of errors

Read this page or join us on Redox Chat.

How to report bugs on Redox

Read this page and check the GitLab Issues to see if your problem was reported.

How do I contribute to Redox?

You can contribute to Redox in many ways, you can see them on CONTRIBUTING.

I have a problem/question for Redox team