ReactOS

π§© 1. Basic Information
Field β>Description
OS Name β>ReactOS
Developer β>ReactOS Foundation & global contributors
First Released β>1998 (as FreeWin95), became ReactOS in 1998
Latest Version β>ReactOS 0.4.15 (alpha, 2024 builds)
License Type β>GNU GPL (kernel), LGPL/MIT (some libs)
Supported Platforms β>x86 (primary), x64 (experimental), ARM (early)
Still Active? β>β
Yes, under active development, but still alpha
βοΈ 2. Kernel & Architecture
Kernel Type: Monolithic NT-like kernel
Based On: Re-implementation of Windows NT architecture (closely follows Windows 2003 Server design)
Fully independent β not based on Linux or Wine, but often integrates Wine DLLs for user-mode compatibility
Uses a Windows-compatible HAL (Hardware Abstraction Layer) & driver model
π 3. Key Features
Can run many Windows apps natively, including older games and utilities
Installs and runs Windows drivers (like for network cards, sound, graphics)
Familiar Windows Explorer-style GUI β start menu, taskbar, Control Panel
Designed to be lightweight, boots fast even on old hardware
Comes with open-source replacements for Windows tools (Regedit, Task Manager, Control Panel)
Integrates Wine DLLs to handle Win32 APIs & compatibility layers
π 4. Version History & Important Milestones β
Version / Milestone β>Year β>Description
FreeWin95 project β>1996β98 β>Early attempts to clone Windows 95
ReactOS formed β>1998 β>Shifted goal to clone Windows NT/2000 architecture
First bootable kernels β>2004 β>Could boot into a primitive shell
GUI & Explorer Shell β>2006Β± β>Started offering graphical environment
ReactOS 0.4.x series β>2016Β± β>More stable releases, USB, networking, NTFS read
0.4.15+ (latest) β>2024β25 β>Continues adding driver improvements, new memory manager, filesystem fixes
π― 5. Target Audience & Use Cases
Retro gamers: runs many classic Windows 95/98/XP games on modern hardware
Developers & testers: test Windows apps without Microsoft licensing fees
Embedded & thin clients: very lightweight footprint
Educational use: learn Windows internals via open source kernel
Still not ready for mission-critical production, but improving steadily
β 6. Pros & Cons
Pros β>Cons
Completely open source Windows-like OS β>Still alpha β crashes & bugs common
Runs many Win32 apps & some drivers β>Not 100% API compatible, especially for newer Windows apps
Low system requirements, very fast boot β>x64 & modern driver support still limited
Familiar UI for Windows users β>No official Microsoft support, small dev team
π¨ 7. UI Demo & Visuals
Boot screen & classic blue setup GUI (similar to Windows XP install)
ReactOS desktop: start menu, taskbar, opening Explorer
Using built-in apps: Calculator, Regedit, Task Manager
Installing classic Windows games (like Winquake, Starcraft demo)
Control Panel showing device manager with Windows drivers loaded
π¦ 8. Ecosystem & App Support
Runs many Windows XP/2003-era software natively (via direct Win32 compatibility)
Compatible with many drivers from Windows hardware vendors
Can install apps like Firefox, LibreOffice, some MS Office versions, classic games
Uses Wine DLLs for user-space Windows API layers (shared dev with Wine project)
π 9. Security & Updates
Kernel development focuses on matching Windows NT security architecture
No built-in antivirus; community recommends using open-source AV tools or scanning from another system
Frequent alpha builds posted on the ReactOS site with changelogs
No official long-term support β itβs a hobbyist / research-level OS still
π 10. Community, License & Development
License: Mostly GPL for kernel & core, LGPL/MIT for userland (Wine, libraries)
Maintained by the ReactOS Foundation, supported by donations & global contributors
Source hosted on GitHub, active Jira bug tracker & nightly build system
Community of developers on forums, Matrix/IRC channels, and YouTube showing compatibility tests