ReactOS

This article or section contains information about computer software currently in development.
The content may change as the software development progresses.

ReactOS

ReactOS 0.3.4 showing the Start Menu
Website	www.reactos.org
Company/ developer	ReactOS Foundation, the ReactOS Community
Source model	Free software
Latest stable release	0.3.4 / January 22, 2008 (2008-01-22), 65 days ago
Kernel type	Hybrid kernel
Default user interface	Graphical User Interface
License	various free software licenses
Working state	Alpha

ReactOS is a computer operating system intended to be binary-compatible with application software and device drivers made for Microsoft Windows NT versions 5.x and up (Windows 2000 and its successors). It is composed entirely of free software, by means of a complete clean room reverse engineering process.

Although the project is in the alpha development stage as of 2008, many Windows programs already work well. While the ReactOS kernel has been written from scratch, the userland is mostly based on the Wine compatibility layer for Unix-like operating systems.

ReactOS is primarily written in the C programming language, with some elements, such as ReactOS Explorer, written in C++. Various components of ReactOS are licensed under the GNU General Public License, the GNU Lesser General Public License, and the BSD License.

1 Development
2 Related projects
3 Hardware requirements
- 3.1 Architecture support
4 See also
5 References
6 External links

Development

FreeWin95 to ReactOS

Around 1996, a group of free/open source software developers started a project called FreeWin95, to implement a clone of Windows 95. The project stalled in discussions of the design of the system.

At the end of 1997, the project had yet to release any software. The project members, led by coordinator Jason Filby, called to revive the project. The project's target was changed to Windows NT and the project's name was changed to ReactOS. The ReactOS project began in February 1998, with developing the kernel and basic drivers.

Version history and roadmap

ReactOS's many APIs and ABIs are ready for a higher level of development and a basic GUI is available. ReactOS features ReactOS Explorer (ROSExplorer), a basic shell similar to Windows Explorer.

ReactOS project coordinator Alexey Bragin (left) shows ReactOS functionality to Viktor Alksnis

Version	Release date	Development stage	Significant changes
0.2.0	March 2004	Alpha	Version 0.2.0 of ReactOS is able to run many Win32 applications, including Notepad (a basic text editor), Regedit (the Registry editor), cmd.exe (the command-line interpreter), and several other applications (such as AbiWord) and basic games (such as Quake and Quake II, and the Wine clone of Minesweeper). Some games like Unreal Tournament and Deus Ex are confirmed to work, using software rendering. OpenGL runs with some minor problems, using the nVidia driver or the software implementation Mesa 3D. The first Web server (Tiny Web Server^[1]) and VNC client (UltraVNC) are reported to work, and OpenOffice.org version 1.x works partly.
0.2.2	April 28, 2004	Alpha	Basic bugfixes and feature improvements
0.2.5	January 5, 2005	Alpha	Large improvements in networking and stability. It was intended to be the last 0.2.x release before 0.3.0.
0.2.8		Alpha	As of Version 0.2.8, some elements of TCP/IP networking work, as well as a better number of applications. Sound and USB support is still being worked on (SB16 works partially, and USB OHCI and UHCI work is still being undertaken). The USB functionality is derived from the Cromwell project. Plug-and-play work has also begun, as has the move to support the Windows Driver Model. In addition to the Lynx text-based browser, ReactOS can use DCOM components from Mozilla to browse web pages graphically. ReactOS 0.2.8 can also detect whether it is running in a VMware environment, and can install the SVGA driver from the VMware Tools ISO, to provide a better level of GUI performance. CSRSS has also been totally rewritten, and a "written-from-scratch" implementation of Winsock 2 is scheduled to arrive very soon. Also present in the trunk are somewhat-working elements of ddraw, dplay, and dplayx.
0.3.0	June 15, 2006	Alpha	ReactOS 0.3.0 Release Candidate 1 was released on June 15, 2006. Improved network (TCP/IP) and Plug & Play support are the headline improvements of this version. Version 0.3.0 Release Candidate 2 was released when the audit reached 94%. It was deemed appropriate to release another candidate version at this time because so many bug fixes had been made during the audit.
0.3.1	March 11, 2007	Alpha	ReactOS 0.3.1 was the first release after the start of a massive kernel rewrite, which made many parts more compatible to NT 5.2. This release also features the addition of a Registry library, which greatly improved the Registry support. An easy tool for downloading popular free and Shareware applications also debuted in this release.
0.3.3	September 12, 2007	Alpha	The release of ReactOS 0.3.3 brought more improvements in the kernel, bringing many areas closer to NT 5.2. It also brought stability increase in many core modules, especially win32k. Version 0.3.2 had been skipped due to many complex blockers, which could not be fixed in the scheduled time frame.
0.3.4	January 22, 2008	Alpha	ReactOS 0.3.4 brought a rewrite of registry support, syncing of DLLs with the Wine project, improved plug'n'play support, improvements to user32, Win32k, many core user mode components, shell32, the Control Panel, and the addition of a remote desktop client.^[2]
0.3.5	April 2008	Alpha	Version 0.3.5 is scheduled for April, 2008, and will continue the improvements made in 0.3.4.^[3]
0.4	2008	Alpha	Version 0.4 is expected to have a 50% compatible Windows NT Kernel, SMB support, initial audio support, Winlogin, support for USB input devices, support for the 5 most common network cards, and networking improvement.^[4]
0.5	2009	Beta	Version 0.5 is scheduled to have a 70% Windows NT compatible kernel, a new ReactOS Explorer shell, Win32k improvements, an LSA Server, a printing subsystem, and a Windows 2003-based storage stack. ^[4]
0.6	Unset	Beta	Version 0.6 is scheduled to have full USB and audio support. It will have ReactX enhancements and be compatible with Visual Studio 2005.^[4]
0.7 - 0.9	Unset	Beta	Versions 0.7 to 0.9 are going to have general improvements and bugfixes.
1.0	Unset	Gold	Version 1.0 is to be a fully stable and complete Windows NT 5.x+ implementation.

Key:	Old Version	Current Version	Future Version

ReactOS running AbiWord and ReactOS Explorer

Current and future development

The ReactOS developers are currently working on support for USB. For this, the Cromwell version of the Linux implementation is being ported. Development is also taking place to add networking, multimedia, plug-and-play hardware support, and improving the GUI system. Java and .NET support (through Mono) has also been stubbed. After a multi-user environment is developed, Terminal Service and Remote desktop will be developed; for this XRDP, Virtual Network Computing (VNC), and rdesktop will be used. Provisions for DOS, OS/2, and POSIX subsystems have also been made, similarly to the Windows NT subsystems.^[5]

The developers aim to make the kernel more compatible with Windows NT versions 5 and 6, and add support for more applications. Improved USB, networking, and other hardware support may also be available, while support for file sharing services with SMB and NTFS file system support may be added. Most of these changes are already underway, while more advanced features will take longer to develop.^[4]

Work is also being done to improve 3D gaming support and complete OpenGL support, and progress is being made in developing ReactX, the project's open-source equivalent of DirectX.^[6]

Internal audit

On 17 January 2006, Hartmut Birr alleged on the ReactOS Developers mailing list (ros-dev) that ReactOS contained code derived from disassembling Microsoft Windows.^[7] As a result of the allegations, the project's developers decided to temporarily suspend access to files of the operating system for non-developers while the contributors were contacted to ensure clean reverse engineering. Since ReactOS is a free/open-source software development project, this action caused a negative reaction by the free software community. Contributors to its development were not affected by this action, and all access to the software development tools was restored shortly afterwards. Though the accusation was unproven, it resulted in controversy and mistrust. Consequently, from March 2006 through December 2007, an internally conducted source code audit was conducted to ensure that only clean room reverse engineering was used.^[8] All developers were also made to sign an agreement ensuring only clean room reverse engineering was used.^[9] In September 2007, with the audit nearing completion, the audit status was removed from the ReactOS homepage. Though the audit has completed, specific details were not made public as it was only an internal effort to ensure legally produced code.^[10]

Related projects

ReactOS works with the Wine project so that the ReactOS project can benefit from Wine's progress in implementing the Win32 API. These efforts mainly concern Wine's DLLs, most of which can be shared between ReactOS and Wine. Both projects work on cross-compatibility issues, so that the remaining few DLLs can be used in ReactOS.

Another related project is Samba TNG, which implements dozens of services, such as LSASS, SAM, NETLOGON, and SPOOLSS, that are key to the success and functionally correct interoperability of the ReactOS project. Samba's architectural design and strategic goals make it a difficult prospect to consider integrating into ReactOS, whereas Samba TNG's multi-layered and modular approach make it far easier to consider porting each service to ReactOS.

Hardware requirements

The minimum hardware requirements for ReactOS to run are:^[11]

x86-compatible processor (Pentium or later)
32 MB RAM
IDE hard disk of at least 150 MB
FAT16/FAT32 boot partition
2 MB VGA graphics adapter (4 MB recommended)
CD-ROM drive
Standard keyboard
PS/2 compatible mouse or Microsoft Mouse-compatible serial mouse

Architecture support

ReactOS developers are currently working on a number of ports of ReactOS:

x86 (working)
Xbox (regressed, but will be revived later)
PowerPC (initial booting)^[12]
ARM (not working, in progress)^[13]

As noted, ReactOS can also be run on software which emulates the above hardware, such as VMware, VirtualBox and QEMU (support for Microsoft Virtual PC is currently unavailable, but may be revived in the future).

As Windows NT 4.0 ran on MIPS, Alpha AXP, and PowerPC architectures in addition to the i386 architecture, and NT-derived operating systems such as Windows XP and Windows Server 2003 have been ported to several architectures (i.e. AMD64, IA-32, and IA-64), ReactOS developers have also taken initial steps in view of portability. For example, support for a variant IA-32 architecture, the Xbox platform, was added to the 0.2.5 release, and efforts toward a ReactOS port on the PowerPC and the Xen architecture are also underway as of 2005. Also currently they are working on porting ReactOS for ARM platform with the hope for a pocketPC-type ReactOS which at this point can fit better than a full featured operating system.