ReactOS Foundation

What ReactOS Foundation does

ReactOS Foundation (legally ReactOS Deutschland e.V.) is a German non-profit association registered in Rheda-Wiedenbrück, Germany, that provides organizational and financial support for the ReactOS Project — an open-source operating system designed for binary-level compatibility with Microsoft Windows applications and drivers. Founded in 2009 to support a project that traces its origins to 1996, the Foundation operates without any corporate parent, government backing, or institutional investors, and explicitly states the project is not supported by any company or government. The Foundation is governed by a board including a President (Matthias Kupfer), Vice Presidents (Daniel Reimer, Pierre Schweitzer), and Treasurer (Colin Finck).

The core product, the ReactOS operating system, implements the Windows NT architecture from scratch — including the kernel, memory manager, NTDLL, kernel32.dll, Plug and Play manager, and a multi-filesystem stack supporting NTFS, FAT, Ext2/3/4, BtrFS, ReiserFS, FFS, NFS, CDFS, and UDFS. The codebase comprises 14.9 million lines of code across 31,025 files and 88,198 commits contributed by 301 unique contributors over 30 years. Supporting tooling includes RAPPS (application manager), FreeLoader (bootloader), Testman (CI test result viewer), and RosBE (build environment). The project maintains bidirectional code synchronization with the Wine project and imports drivers from the Windows Driver Kit. The current release (0.4.15, March 2025) remains in alpha stage and is positioned primarily for experimentation rather than production use.

ReactOS generates no commercial revenue. The OS is distributed free via ISO downloads from reactos.org and the GitHub repository, with nightly builds available for testing. The Foundation's only revenue stream is voluntary community donations via PayPal, wire transfer, Bitcoin, and WebMoney, used to maintain server infrastructure and fund occasional contractor work. All development is volunteer-based. Go-to-market is purely community-led: the project acquires users and contributors through GitHub, forums, Mattermost chat, mailing lists, social media, Google Summer of Code, and open-source conferences. Customer segments are individual hobbyists, open-source enthusiasts, and developers studying Windows NT internals — there are no enterprise customers or commercial distribution channels.

Name

ReactOS Foundation

Legal name

ReactOS Deutschland e.V.

Website

https://reactos.org

Company type

Private

Founded year

1996

Operating status

Operating

Headcount range

101–250 employees

Short description

ReactOS Foundation is a German non-profit that supports the ReactOS Project, an open-source operating system providing binary-level Windows application and driver compatibility. It serves individual hobbyists, open-source developers, and researchers, funded entirely by community donations with no commercial revenue.

Ownership category

akta.pro rank

Product category

Open-Source Operating System

NAICS

Software Publishers (5132), Computer Systems Design Services (541512)

SIC

Services-Prepackaged Software (7372), Services-Computer Programming Services (7371)

akta.pro primary industry

Release Engineering & Environment Management (BPAEAKAH)

Keywords

• Open source operating system
• Windows compatibility layer
• Binary compatible OS
• Desktop operating system
• Operating system development

Headquarters

HQ city

Berlin

HQ country

Germany

HQ region

Europe

Offices1 record

Markets served

GTM type

B2C

Offering type

Software

Cost components

Personnel, Technology or R&D, Infrastructure, Operations

Revenue model

1. Donations: ReactOS operates as a non-profit and relies entirely on donations from the community. Donations are used to maintain server infrastructure and fund specific development tasks through contractors. No commercial revenue model exists.
2. PayPal and Wire Transfers: ReactOS accepts one-time and monthly recurring donations via PayPal and bank wire transfers. PayPal and wire transfers are tax deductible. Contact email provided for donation receipts.
3. Cryptocurrency Donations: ReactOS accepts Bitcoin and WebMoney donations, providing options for donors who prefer non-government controlled currencies or in countries where PayPal is unavailable.

Pricing tiers

Go-to-market motion2 records

Distribution channels3 records

Marketing channels8 records

Core offering

ReactOS is an open-source operating system based on the Windows NT architecture that achieves binary-level compatibility with Windows applications and drivers, allowing users to run unmodified Windows software in a free, auditable environment. The project includes the core OS (kernel, memory manager, file system drivers, USB/audio/graphics stacks, shell) plus supporting tools such as RAPPS application manager, FreeLoader bootloader, Testman CI test platform, and the RosBE build environment. The software is distributed free of charge as ISO downloads and source code, with development supported entirely by community donations.

Product overview

ReactOS is a single unified open-source operating system product designed to be binary-compatible with Microsoft Windows. The core offering is the ReactOS OS itself, with versioned releases (0.4.x series) providing incremental improvements. Supporting tools include RAPPS for application management, FreeLoader as the bootloader, Testman for CI/CD testing, and RosBE for the build environment. The project syncs code with the Wine project and accepts contributions via GitHub.

Differentiator

Problem solved

Functional benefit

Products and services

• ReactOS Operating System Open-source operating system built on the Windows NT architecture that achieves binary-level compatibility with Windows applications and drivers. Includes a kernel, memory manager, multi-file-system support (NTFS, FAT, Ext2/3/4, BtrFS, ReiserFS, FFS, NFS, CDFS, UDFS), USB stack, audio drivers, WDDM/XDDM graphics drivers, Plug and Play manager, and a Windows-like shell. Distributed free of charge for experimentation, research, and learning. Currently in alpha stage.
• RAPPS (ReactOS Application Manager) Built-in package manager for ReactOS that enables users to discover, download, and install a variety of applications. Supports multiple languages and includes features such as bulk downloads, background installation, and install progress indicators. Targeted at ReactOS end users who need an integrated app installation experience.
• FreeLoader ReactOS bootloader responsible for loading the operating system. Supports reading from multiple file systems including FAT, EXT2, BTRFS, and the loading of custom kernels and HALs. Enables booting on diverse hardware configurations and legacy platforms.
• Testman CI/CD testing platform integrated into the ReactOS website that displays automated test bot run results. Allows contributors and developers to view and analyze test results for pull requests. Includes both custom ReactOS tests and Wine-sourced tests validated against Windows Server 2003, Vista, 7, 8.1, and 10 for x86 and x64 architectures.
• ReactOS Build Environment (RosBE) Curated set of compilers and build tools that provide the development environment for building ReactOS from source. Distributed to contributors and developers who compile ReactOS. Used for self-hosting capability, enabling ReactOS to compile itself.

Quantifiable outcome

• Supports running GPU drivers from Intel, Nvidia, and AMD through reverse engineering
• +2 more outcomes

Named customers3 records

Segments3 records

Ideal customer profiles3 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Integration3 records

Feature7 records

Partnerships

Two partnerships are on record, tiered core.

• Google Summer of CodecoreStrategic or Co-development Partner · 1 January 2006ReactOS participates in Google Summer of Code annually, pairing students with mentors to work on ReactOS development projects. Past GSoC projects have included NTFS driver development, file search features, RAPPS enhancements, USB stack improvements, and kernel fuzzing tools. The program has produced significant contributions to the project.
• Wine ProjectcoreTechnology or Integration · 22 January 1996ReactOS shares code and syncs tests with the Wine project, an open-source Windows compatibility layer. ReactOS imports Wine's user-mode DLLs and test suites, adapting them for its NT-based architecture. The relationship is bidirectional as ReactOS developers also contribute patches back to Wine.

Scale indicators8 records

Recent moves6 records

Expansion highlights4 records

Emerging players

• Qubes OS: Qubes OS is a security-focused open-source operating system built on a community model. It shares ReactOS's positioning as a niche open-source OS targeting a specific user community (security) rather than general consumers.
• Haiku OS: Haiku is a community-driven, open-source recreation of BeOS. Like ReactOS, it is a niche open-source OS project aiming for binary compatibility with a proprietary predecessor, built largely by volunteers over many years with limited commercial revenue.
• KolibriOS: KolibriOS is a small, open-source x86 operating system written largely in assembly by hobbyist contributors. It is comparable to ReactOS as a niche, volunteer-built open-source OS with a tight community.
• FreeDOS: FreeDOS is a free, open-source DOS-compatible operating system. It parallels ReactOS in its mission to provide a free alternative to a Microsoft OS platform via volunteer community development.
• SerenityOS: SerenityOS is a hobbyist-driven, from-scratch open-source operating system with a Unix-like architecture. It mirrors ReactOS's community-development model and long-term vision of building a complete modern OS outside corporate control.

Broad incumbents

• FreeBSD: FreeBSD is a mature, broadly-used open-source operating system. While not Windows-compatible, it shares ReactOS's open-source OS category and is a comparable institutional-scale community project.
• NetBSD: NetBSD is a long-established open-source Unix-like OS emphasizing portability. It is comparable to ReactOS as a long-running community-governed open-source OS project, though much further along in maturity.

Direct peers

• Wine Project: Wine is an open-source Windows compatibility layer for Linux/Unix. It is ReactOS's most direct peer: both projects aim to enable unmodified Windows applications to run on non-Microsoft platforms, share code bidirectionally, and maintain aligned user-mode DLLs and test suites.

Others

• Cygwin: Cygwin provides a POSIX compatibility layer on Windows. While smaller in scope than ReactOS, it is thematically adjacent — both projects address cross-platform compatibility between Windows and other computing paradigms via open-source tooling.
• GNU Hurd: GNU Hurd is the FSF's long-running open-source microkernel-based OS project. It is comparable to ReactOS as another decades-old community open-source OS effort that has struggled to reach mainstream usability.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat4 records

Key risks6 records

Key highlights7 records

Customer concentration

• GitHubgithub.com/reactos/reactos
• Xx.com/reactos
• Facebookfacebook.com/19143619259
• LinkedInlinkedin.com/company/reactos-foundation

Revenue estimate

Valuation estimate

Number of profiles

Profiles4 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about ReactOS Foundation