Information Density: ReactOS Project – Signal Evidence & AI Readability

[H1] Welcome to ReactOS
Imagine running your favorite Windows applications and drivers in an open-source environment you can trust.
That's the mission of ReactOS!

[H4] Development

ReactOS Builds
Report a Bug
Testman
Wiki

[H4] Get in touch

Chat
Forum
Mailing Lists

[IMG: ReactOS in action]

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Download ReactOS 0.4.15 or
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For the latest features and bugfixes, try our nightly builds.

[H3] Recent News

[H2] 30 years of ReactOS

by Carl Bialorucki

January 22, 2026

Happy Birthday ReactOS! Today marks 30 years since the first commit to the ReactOS source tree. It’s been such a long journey that many of our contributors today, including myself, were not alive during this event. Yet our mission to deliver “your favorite Windows apps and drivers in an open-source environment you can trust” continues to bring people together. Let’s take a brief look at some of the high and low points throughout our history.

[H2] Progress update: fixing the ReactOS test suite

by Carl Bialorucki

November 4, 2025

For many years, the ReactOS test suite was neglected. It was a random collection of our own tests and old Wine tests that were only checked against Windows Server 2003 and sometimes a random newer version of Windows up to the discretion of the contributor. The Wine tests we imported were heavily modified and the changes made weren’t always well documented.
I’m here to clean up this mess.
I have been deeply involved with the ReactOS project since 2023 and in May of 2024 I became an official project developer.

[H2] An initial investigation into WDDM on ReactOS

by The_DarkFire_

October 7, 2025

The history of ReactOS spans a wider range than the lives of many of the people who work on it today. Incredible individuals have come and gone from the project with vastly different goals for what they want to see developed. In recent years, better hardware support has emerged as one of those goals. As ReactOS gazes towards the world of Vista and beyond, a few questions about how hardware works emerge.

[H2] Carl Bialorucki hired to improve ReactOS test suite

by Carl Bialorucki

July 4, 2025

Hi, my name is Carl J. Bialorucki.
I started making a name for myself in the ReactOS community by contributing several shell improvements.
In May of 2024 I was added to the core development team and in March of 2025 I led the release of ReactOS 0.4.15 after the previous release manager was unable to continue working on the project.
I’m pleased to announce that I was hired for a full-time contract position with ReactOS Deutschland e.V. in May of 2025.

Older posts →

[H3] Live Activity

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/ gallery

[H1] Gallery

[IMG: Applications Manager]

Applications Manager
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File Search
[IMG: Mizu Theme]

Mizu Theme
[IMG: Lautus Theme]

Lautus Theme
[IMG: ReactOS Luna XP Theme]

ReactOS Luna XP Theme
[IMG: Windows 3 Classic Theme]

Windows 3 Classic Theme
[IMG: Ext2 Volume Manager]

Ext2 Volume Manager
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Explorer++
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7-Zip
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WinRAR
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WinZIP
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XnView
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VLC
[IMG: Media Player Classic]

Media Player Classic
[IMG: PuTTY]

PuTTY
[IMG: ReactOS on VirtualPC 2007]

ReactOS on VirtualPC 2007
[IMG: SimCity 3000]

SimCity 3000
[IMG: Neverball]

Neverball
[IMG: Teeworlds]

Teeworlds
[IMG: AssaultCube]

AssaultCube
[IMG: Epiphany]

Epiphany
[IMG: Picodrive]

Picodrive
[IMG: Papers Please]

Papers Please
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LibreOffice Writer
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LibreOffice Calc
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Excel Viewer
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Word Viewer
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FoxIt Reader 7
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HexEdit
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HxD
[IMG: Gimp]

Gimp
[IMG: Krita]

Krita
[IMG: Mozilla Firefox]

Mozilla Firefox
[IMG: Mozilla Thunderbird]

Mozilla Thunderbird
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FileZilla
[IMG: HFS HTTP File Server]

HFS HTTP File Server

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/ contributing

[H1] Contribute to ReactOS

The ReactOS Project always seeks new qualified contributors from all skill levels.
No matter if you are a developer, tester, editor or designer, your contribution is highly appreciated.
Please see below for all available positions and contact us via Mattermost or the mailing lists.
Every year we participate in Google Summer of Code which is a program by Google that lets you work with us during the summer to work on a major project.
Google pays the student, and ReactOS provides guidance and assistance in the form of a mentor.
Check our Wiki page for more information.
We also conduct Hackfests every year where our team comes together to socialize and work on issues together.
[H2] Kernel Developer
For the ReactOS Kernel and drivers, we are looking for people proficient in C, and it is a big plus if you are proficient in C++ too. C++ proficiency does not equate C proficiency, so do not assume you have the latter if you have the former. Also keep in mind, again, that these are the minimum requirements. On top of these you need to be a good problem solver, believe in the mission of ReactOS, and most importantly, be able to demonstrate that you can work with the ReactOS codebase via a few pull requests.
If you qualify for this position, you’ll be joining the very small and exclusive ranks of people who know how to do NT systems development.
And believe us, those ranks are very, very small so you will be gaining an immense amount of knowledge working with such people.
It’s a great experience to interact with people who have been working in this field for over the years.
[H2] Application Developer
ReactOS User-Mode applications are written in C or C++.
You can have a look at Win32 development using C++ to get started with developing GUI applications using the Win32 API.
Also check our Development Introduction wiki page which pretty much covers all of the details on getting started with development for ReactOS.
[H2] Web Developer
The ReactOS Infrastructure builds upon several components written in PHP.
If you are comfortable in PHP and want to help improving this website and the tools ReactOS developers use, don’t hesitate to contact us.
[H2] Tester
No operating system is usable if it is found to be unstable and prone to crashes. As ReactOS development work involves studying the behavior of an operating system that is not completely documented, testing is of even greater importance in order to fulfill the objective of binary compatibility with Windows.
You can assist the ReactOS development effort by installing regular nightly (master) builds available here and providing feedback on issues/problems you encountered during and after installing the OS via our bug tracker.
More information regarding debugging is available here and is recommended reading for those who wish to submit a report to our bug tracker.
For this, you need to have basic knowledge in collecting information from a crash like backtraces and crash dumps. Knowledge of using a basic debugger is a plus.
We have several Wiki pages for setting up a debugging environment and building using different compilers too:
Setting up a Debugging environment
How to create a JIRA Issue
[H2] Jira Maintainer
We use Jira to keep track of issues.
This position is for people interested in maintaining Jira.
You will have to look after the development/work progress in the bugtracker and assist in triaging the issues.
This includes but is not limited to: Asking for the exact version that was tested, disseminating logs (or asking further steps to provide those), labeling issues.
[H2] Content Editor
The best operating system is pointless if nobody knows about it.
As a team of mostly developers, we need some creative people to post content to our website and social media accounts (such as Facebook and Twitter).
In this role, you will write articles, make changes or update the Wiki pages.
Our current site is generated using Hugo.
New design ideas are welcome too.
[H2] Community Manager
The ReactOS community keeps in touch via Mattermost and our forums.
The role is to keep people involved, keep discussions going and moderate.
[H2] Translator
Localization is fundamental for an operating system to be used by many users around the globe where English is not their mother tongue.
If there’s a language that ReactOS is not currently translated in or you like to improve the current existing translation in the operating system please take a look at the following article at how to begin translating ReactOS.
[H2] Paid jobs
While ReactOS is an open-source project mostly driven by volunteers, we know that some tasks could profit from having a paid developer look at them.
ReactOS Deutschland e.V., the non-profit organization supporting the ReactOS Project, has been collecting donations for this purpose and supports several models for paid development:
Scholarships
Interested students with a proven track record of working on ReactOS can be granted a monthly scholarship (which is tax-free in many countries).
This requires enrollment at a university but hardly any paperwork.
Contracted work
Freelancers able to invoice ReactOS Deutschland e.V. can be contracted for individual work that benefits the project.
This requires a proven track record of working on ReactOS-related topics as well as a detailed proposal.

ReactOS Builds are automatically built by our BuildBot each time a change is committed to the ReactOS Repository. This way, they incorporate latest fixes. However, they are not as thoroughly tested as the release builds. You may find regressions and bugs.

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[H3] Legend
Boot CD - Boot CDs are designed to install ReactOS onto an HDD and enjoy the new features since last release. You will need the ISO only for the installation. This is the recommended variant to install into a VM (VirtualBox, VMWare, QEMU).
Live CD - Live CDs allow you to use ReactOS without installing it. It can be used to test ReactOS in case your HDD is not detected during installation, or if you have no alternative system/VMs to install it on.
Debug - Debug versions include debugging information, use these versions to test, produce logs and report bugs. This is the recommended variant to install to report bugs.
Release - Release versions include no debugging information. These versions are smaller, but cannot be used to produce logs.