Aleksey Bragin | 7 Nov 11:49 2014

ReactOS 0.3.17 Released

The ReactOS Project is pleased to release version 0.3.17.

A major new feature for this release is the inclusion of NTVDM, which 
provides support for a wide range of 16bit applications, a long 
requested feature by the community. NTVDM is still undergoing work but 
we felt that it was ready enough to provide a sneak peak to the wider 

In addition, the leadup to the 0.3.17 release saw a very impressive 
round of testing by the community. Several regressions and bugs 
discovered in the release candidates were promptly fixed and 
incorporated into the final release.

ReactOS is quickly approaching a stage where what the releases will 
offer is polish compared to previous releases. That will be an important 
milestone, as it is then that we can begin recommending to people that 
they try using ReactOS for day-to-day computing.

We hope you look forward to it as much as we do.

The detailed 0.3.17 changelog is also available:

Main news link:
Download link:
Ziliang Guo | 10 Apr 04:39 2014

Indiegogo Campaign

As some of you know the ReactOS Project recently launched an Indiegogo campaign
( to fund development of a
Community Edition where backers get a say in priority for software and hardware support. The project has
been going strong but we're still a long way from the finish goal.

Backers can choose from a range of rewards from votes for their desired hardware or software to
collectables like USB sticks, shirts, and the elusive Hackbunny of yore to even getting your name
embedded into the Community Edition. Who knows, depending on how well we do, there might even be cake. So
come on by and show your support. Together we can make the dream that is ReactOS a reality.
Ziliang Guo | 24 Jan 18:16 2014

ReactOS/Thorium Core Kickstarter

The ReactOS project recently initiated a Kickstarter campaignin the form of Thorium Core, a cloud desktop environment that allows one to have a consistent computing environment with the same applications and settings anywhere one has a reliable broadband connection. To achieve this, Thorium intends to complete the work needed to bring ReactOS to a state where it is useable for day to day activities as well as tune it for usage in various virtual environments. Due to ReactOS' lightweight nature, a Thorium Core instance will have more resources to dedicate to the things that matter most to a user, running their applications.


Of course, Thorium isn't about just a cloud desktop. It's very much about ReactOS itself. The project has gotten close, very close, to being ready for general use. Rough edges are being polished at a daily rate and in the preparation for 0.4.0, the team has put significant effort into not just the system's stability but also the user friendliness of a new explorer shell. With Thorium's success, the project can work on other issues that stand in the way of ReactOS being ready for day to day use. So for ReactOS supporters, Thorium offers the chance to bring ReactOS out of alpha, into beta, and maybe even into production. If you've been waiting years for ReactOS to be to the point where you can replace your soon to be retired Windows XP install, then here's a chance to help the project make that final push to be ready.

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Ziliang Guo | 30 May 17:33 2013

ReactOS 0.3.15 Released

The ReactOS project is proud to announce the release of version 0.3.15. A culmination of over a year of
development, 0.3.15 incorporates several architectural enhancements to create a more compatible and
conformant implementation of the NT architecture. Perhaps the most user visible enhancement is initial
support for USB devices, both storage and input.

Infrastructure wise, this is the first release of ReactOS using CMake instead of rbuild. The conversion to
CMake has allowed developers to generate Visual Studio solutions for working on the code, though several
C++ components still need work before support for Microsoft's toolchain is complete.

The importance of 0.3.15 is not just its release but what it promises. Feedback from testers helping with
finalizing the release provided a host of data that developers used to fix a wide range of issues. It is
often said that each release should be better than its predecessors. 0.3.15 certainly fulfills that
criteria but also promises much better for the future.

Some highlights of this release are as follows

* Preliminary support for USB mice, keyboard, and storage devices.
* A rewritten session management subsystem
* ARM3 has taken over all memory management responsibilities except for sections.
* AHCI support with updated UniATA driver
* Preliminary support for debugging ReactOS components using windbg
* Improvements based off results from the AutoHotKey application functionality test suite
* Bugfixes based off running Driver Verifier on several bundled drivers

In addition to the packages traditionally provided by the release, there is an additional image of a hybrid
CD used at the LinuxTag expo to showcase ReactOS. This image incorporates some additional USB related
fixes to allow for more robust initialization and detection of devices along with enabling of the Lautus
theme by default. Please note that theme support is still incomplete and the use of Lautus in the LinuxTag
hybrid CD was primarily for showcase purposes and is not yet ready for general use.

The detailed 0.3.15 changelog is also available:

Main news link:
Download link:
Aleksey Bragin | 2 May 00:16 2012

Please read: A personal appeal from ReactOS Project Coordinator Aleksey Bragin

Normally this list is used to announce new releases of ReactOS operating system, however this time is an exception. There is a significant, rare event which I would like to get your attention to.

ReactOS Fundraiser 2012.

The ReactOS Project has engaged in several fundraising efforts in the past, and thanks to their success and non-monetary donations, an industry-grade infrastructure was developed and deployed, and is being continuously improved.

Donations have also helped developers travel to several conferences and events to promote and present ReactOS. These presentations were crucial in drawing attention to the project and often helped spur further donations.

This year we want to do something different, something even grander. ReactOS is quite close to transitioning to beta testing and we are constantly improving the development process itself. However for many core developers ReactOS remains a hobby in which they participate in their spare time as all have other real life obligations to meet. All of the developers are extremely skilled and every contribution they make helps significantly improve ReactOS' quality.

For the first time ever, the ReactOS Foundation seeks to go beyond the usual small fundraising campaigns aimed at paying infrastructure expenses. We wish to raise money to formally hire as many core developers as possible, to work on the project they believe in, the project they've been working on, to transform a hobby into a job so they can dedicate all of their time to the ReactOS project.

In light of the significant advances the project enjoyed thanks to work done as part of Google's Summer of Code 2011, it became even more obvious that the fastest way to accelerate the development of ReactOS is by directly funding developers to contribute to ReactOS. As such, the project is reaching out to our many fans and believers to help make this happen.

Together, we can make ReactOS into a true competitor and alternative for computer users worldwide.

Aleksey Bragin
ReactOS Project Coordinator

Official news text: (other languages may be available)
ReactOS Fundraising Campaign 2012 Progress bar (updated daily): on top of the page.
Donation page: (other languages may have country-specific ways of donation)

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Aleksey Bragin | 8 Feb 11:38 2012

ReactOS 0.3.14 Released

The ReactOS team is proud to announce the release of ReactOS 0.3.14.

This version includes a significant amount of changes including both 
user visible and architectural improvements. Also included in this 
release is the valuable work accomplished as part of the Google Summer 
of Code 2011 event, of which ReactOS was a mentoring project.

One of the more significant sets of improvements was to ReactOS’ 
networking stack. As part of the GSoC, ReactOS gained a new TCP/IP 
driver built around the LwIP project. The LwIP library is a popular and 
stable implementation of TCP/IP originally intended for embedded use. 
The new driver has significantly increased both stability and 
performance, allowing the use of high bandwidth applications such as 
torrents. Furthermore, ReactOS has improved compatibility with NT5.1 
drivers with the export of scatter/gather DMA functionality. Last but 
not least, ReactOS now includes wireless network support and is able to 
connect to both open and WEP encrypted networks.

One of the more obvious user visible changes includes the implementation 
of theme support. Users can now change the look and feel of ReactOS’ 
user interface by installing XP based themes and changing the appearance 
of the desktop from the default classic look to something more exciting.

Architecturally, the addition of a kernel mode testing framework has 
helped to identify a variety of bugs in kernel mode components. This is 
an important change with regards to core stability and is proving 
invaluable in ensuring the project does not suffer unexpected 
regressions in the kernel.

Support for building ReactOS using the Microsoft toolset has also played 
a large part in the release. This is now at a stage where ReactOS can be 
entirely built using an MSVC based environment and can produce a working 
boot and livecd. Along with GCC, ReactOS can now be built using two 
different toolsets and on a variety of platforms including Windows, 
Linux and Mac OS X.

During the preparation of this release 789 bugs were fixed, including 
118 regressions with the oldest regression being issue #1009 (can't open 
context menu with Shift-F10). The oldest bug fixed was #209 (PrintScreen 
doesn't work) from over eight years ago. 811 new bugs were opened since 
the release of 0.3.13.

A list of some of the more significant changes includes:

Advanced Configuration and Power Interface support is now enabled 
automatically when the ACPI Hardware Abstraction Layer is used, 
providing support for power buttons and full system power off.

* LwIP
A new TCP/IP driver using the LwIP driver has been integrated into 
ReactOS, significantly improving network performance and stability and 
also presenting an upgrade path to IPv6.

* MSVC Compatibility
ReactOS can now be built using Microsoft's compiler to create a working 
boot or livecd.

* Scatter/Gather Support
Scatter/Gather DMA operations are now supported, significantly improving 
compatibility with network drivers written for NT5.1 and later.

* Shell Improvements
The shell32 library rewrite in C++ has been merged in and brings with it 
various architectural improvements that will help serve as a foundation 
for future work on the new explorer shell.

* Special Pool
A special pool designed to guard against misuses of kernel pool memory 
has been implemented.

* Theme Support
ReactOS now has the infrastructure needed to theme the user interface 
and shell, allowing users to install and use something besides the 
classic Windows theme.

* WiFi Support
ReactOS now supports wireless network drivers and is able to join open 
and WEP encrypted wireless networks.

The detailed 0.3.14 changelog is available here:

Main news link:
Download link:

I would like to thank all the past and present members of the ReactOS 
team for their hard work and of course all those in the community that 
support us.
We will never forget involvement and contribution of those who left our 
world too early.

Aleksey Bragin
ReactOS Foundation President
Aleksey Bragin | 22 Mar 17:19 2011

ReactOS 0.3.13 Released

The ReactOS team is proud to announce the release of ReactOS 0.3.13.

This version continues building on the work first previewed in 0.3.12, ranging from memory management improvements to better sound and display control. A Coverity scan also occurred between 0.3.12 and 0.3.13, helping the team clean up potential security holes and also help improve general stability by enforcing more care in memory operations.

Some of the biggest system changes happened with memory management with the introduction of a new heap manager based on the Windows 2003/Vista architecture, significantly increasing ReactOS’ compatibility with advanced memory allocation types and providing proper kernel mode heap management used by win32k. Performance should also see a significant boost for many memory operations even without the addition of optimizations on top of the new heap. The addition of a debug heap manager late in the release cycle also spurred on a series of fixes to memory usage across ReactOS, from the operating system to bundled applications. These changes should significantly improve system stability, moving ReactOS one step closer to being a viable daily use operating system.

Other improvements include the merging in of work done in the yarotows branch for improved display driver loading and dynamic mode changing, significantly increasing ReactOS’ usability.

During the preparation of this release, 282 bugs were fixed, including 50 regressions with the oldest regression being issue #4811 ("comctl32.dll sync broke Abiword toolbar"). The oldest bug fixed is #1567 "Taskmanager still showing processes while they are closed" (almost 5 years old). 382 new bugs were opened since the release of 0.3.12.

Previous releases 0.3.11 and 0.3.12 were downloaded 238 and 526 thousand times, which totals up to an amazing amount of 764 000 downloads, and a significant increase looks very promising.

Some of the most important changes:

  • Implemented dynamic video mode switch and improved graphics drivers compatibillity.
  • Fixed several graphic issues.
  • Completely rewritten heap manager with additional debugging capabilities for detecting out of bounds operations.
  • Improved management of audio mixer lines, preventing application sounds from becoming garbled due to overlapping lines.
  • Heavy bug fixing in user subsystem ( improved handling of user mouse input, messages and timers).
  • Visual artifacts fixed in some apps as Firefox and Thunderbird.
  • Fixed several bugs in the installer.
  • Improved apps compatibility: Stellarium 0.10.2, LHelp, winpcap,FlashPlayer 10.1 and Mono 2.8, OllyDbg 1.10, Xenon 2000, VLC 1.1.5, Foobar 2000, Skype 4.0.0 work now.
  • More SATA devices are supported.
  • Lots of test cases were fixed.
  • Many improvements in the memory manager that fix several bugs and make it more compatible with NT memory manager.

The detailed 0.3.13 changelog is also available. 

Aleksey Bragin
ReactOS Foundation President
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Aleksey Bragin | 20 Oct 21:39 2010

ReactOS 0.3.12 released

The ReactOS team is proud to announce the release of ReactOS 0.3.12.

This is a huge release for the team, not just with regards to the number of improvements which this release holds but in terms of the leap forward architecturally, stability wise and in bringing some of the more modern aspects of the NT kernel into ReactOS.

It's been almost a year since the last release and whilst this is understandably excessive, it was required to stabilize the OS due to the nature of the work which was undertaken. Focus at the start of this release was on a single area, the trap handler mechanism, which resulted in a complete rewrite of this area. This brought with it the need for more changes which escalated into many areas getting an overhaul and many new technologies being developed and brought into the core. What resulted from this was a vastly more modern kernel containing code which had been exercised significantly less than the code it replaced. This triggered a large testing phase to bring the stability and compatibility to levels above that of the previous code.

During the preparation of this release, 259 bugs were fixed, including 61 regressions some of which originated from ReactOS 0.3.7. Ten of those bugs are more than 3 years old, with the oldest fixed bug being #969 (5 years old).

A heavily cut down list of some of the more major changes which have been going on in the past year is as follows:

Memory Manager - The memory manager continued to see much work as the ARM team replaced each component piece by piece whilst also maintaining the functionality of the old manager.  Although 0.3.12 does not completely switch over to the new manager, what is obvious are the speed, stability and compatibility improvements of this new model. 
NMI support - ReactOS can now handle NMIs with a Red Screen of Death, useful for capturing hardware errors detected by the CPU or Bus. Additionally, support for 3rd party NMI callbacks has been implemented, which is useful for certain server systems. Finally, support for generating a crash dump during an NMI is partly implemented, which can help when a machine is frozen or hung and an external NMI dump switch is used.
Trap Handler Rewrite - Almost all CPU faults, trap, exception, and system call code is now written in C instead of Assembly. Many legacy and/or deprecated code paths have been disabled and performance-heavy debugging paths disabled by default. Additionally, the x64 and ARM ports now share much more of this code. Finally, the code is much cleaner and can take advantage of compiler optimizations to generate the best possible code for the CPU instead of writing hand-crafted assembly that was specific only to certain CPU models. Work is ongoing to remove even more of the last remaining Assembly routines.
EMS - Support for Emergency Management System (or Headless) has been partially implemented. The boot flags documented by Microsoft are supported, and certain debug output is sent to the serial port as expected. Work is ongoing to provide the EMS logging capabilities and to move the existing legacy KDBG debugger over EMS. SAC (Special Administration Console) driver work is also in progress to compliment this.
PnP Compatibility - Various improvements have been done to increase hardware support and support for loading 3rd party drivers.
ACPI Improvements - The ARM team has implemented the basic drivers required for supporting batteries and 3rd party UPS/battery drivers, including support for the ACPI Composite Battery specification. This support is not currently enabled in this release because ACPI is still undergoing work.
New PCI-X driver - The ARM team has been slowly working on the new PCI bus driver. Previously, ReactOS was using a very simple and mostly stubbed PCI bus driver which lacked support for many real-world PCI bus features, PCI-to-PCI bridges etc.  With this new driver, compatibility on real hardware, not just virtual machines, should improve significantly, along with performance.
SxS support – Side-by-side code was added, along with loading and finding manifest files. It’s an important step forward to be compatible with modern applications which use this technology.
Pool Corruption Fixes - Perhaps the most serious of these suspected leaks were fixed thanks to combined efforts of key ReactOS developers utilising advanced methods including a customized version of QEMU virtual machine.
Timer and message handling rewrite - Incorrect handling of non-queued messages led to deadlocks in some applications which the message handling rewrite resolved. The timer implementation rewrite is also completed by this release which fixes many timer-related problems, most known is the “need to move mouse in order to download in FireFox”. 
x64 build - While the x64 port is still in an early stage regarding the functioning of the kernel, most of the generic compilation issues are resolved and necessary core functionality implemented. These efforts have been merged back into trunk, so that trunk can be compiled for x64 target. With the help of automatic builds, possible breakages can now quickly be detected and resolved. Don't expect it to boot to GUI though!

The changelog <> for 0.3.12 is also markedly different from previous releases, with an emphasis on conveying an understandable and concise summary of major changes in the release.  Thus instead of duplicating that summary here, we invite you to peruse its contents and see what has been accomplished.

Whilst the ReactOS team has still been attending many public events and conferences in various different countries, we’ve been out of the news due to what may appear as a quiet patch or a lull in activity. We hope this release will go some way to show that we’ve been busier than ever behind the scenes.

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Ged Murphy | 19 Dec 14:17 2009

ReactOS 0.3.11 Released

The ReactOS team is proud to announce the release of ReactOS 0.3.11. This release has been delayed by quite some time due to various blocker bugs which manifested each time we tried to release. A lot of time has gone into hunting down these bugs and various steps have been taken to try to ensure we don't hit this problem again. This isn't to say we don't have a lot of new and exciting features in this release. Two of which stand out are the huge changes to the Memory Manager and another leap forward for the sound stack

It's difficult to sum up all of the changes which have taken place in the memory manager short of saying it's been almost a total rewrite. These changes have not only brought a much more stable and reliable component, but also now includes support for ARM processors. ARM memory management units (MMU’s) are handled in an entirely different manner than that of x86 and x86-64 MMU’s, however the ARM Mm component has been written alongside the x86 component with various areas sharing code when possible. Further to this, these changes bring much improved compatibility with WinDbg. WinDbg support is now at a level where the majority of everyday features are working and tasks which previously seemed so distant using WinDbg, such as stepping through the kernel, listing process threads or dynamically editing memory are now working. We're now at a level where having PDB's (Microsoft's debugging symbols) would make debugging the reactos kernel a similar experience to debugging the Windows kernel, with the added advantage of source mode.
For the technically inquisitive, here are the Mm changes in this release

The sound stack continues to see extensive work throughout all areas. This release brings with it support for wave recording and mixer support such as volume level adjustment and muting. Improved core component compatibility with WinXP means that more components now run within Windows and goes some way to showing the level of compatibility the sound stack is now achieving.

Compatibility and stability changes have been continuing throughout the entire operating system with a great deal of fixes coming from the Wine test framework used to ensure application interface compatibility.

As this is the 0.3.11 release, we felt a certain degree of nostalgia towards 'Windows 3.11 for workgroups' and added a fun easter egg in tribute. See if you can spot it, the older generation will surely have no problems

Along with the rest of the 0.3 series, this release is still considered alpha quality software so it may not run all your apps or run on your hardware.

Changes summary

A detailed consolidation of all changes can be found in the changelog. A sum up of some of the more important changes is as follows:

  • A rewrite of the kdcom kernelmode library which is now much more compatible with the Microsoft version. This allows for improved built-in support for WinDbg

  • Support for delay loaded dlls has been added in our build tools, providing delay loading functionality for our shipped libraries

  • Support for Chinese and Korean fonts has now been added

  • A new handler has been written for setting and getting system wide parameters (see SystemParametersInfo API), now making it much more complete and compatible with the Windows implementation

  • A selection of application compatibility improvements can now been seen, including Opera, Open Office, Firefox 3.5, VLC1.1 and skype

  • For fun, a new Spider Solitaire application has been added

  • Synchronization of most of the Wine usermode DLLs and some Win32 subsystem code shared with Wine

VirtualBox install note

A bug has surfaced meaning that installing ReactOS in VirtualBox will result in a hang when loading the USB driver, unless the VM has 256Mb RAM or more. To counteract this, either raise the RAM from the default 192Mb or disable the USB device. We have created a preloaded VirtualBox VM for download incorporating this workaround. Apologies for any inconvenience caused.

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Aleksey Bragin | 7 Jul 08:58 2009

ReactOS 0.3.10 Released

The ReactOS team is proud to announce the release of ReactOS 0.3.10.  
This version is the first to use the Universal ATA driver as the  
default disk driver, adding support for Serial ATA and partitions  
greater than 8GB. In addition, recent work was done on the USB stack  
to increase compatibility with USB keyboards and mice. These features  
are still under heavy development and have several known bugs, but  
their inclusion should allow more people to run ReactOS on real  
hardware and are part of the extensive work to make ReactOS usable as  
an every day operating system.

Apart from that, ReactOS made it into the final round of the  
SourceForge Community Choice Awards. If you like it, you can vote for  
us ( ) in the  
categories Best Project, Best Project for Government and Most Likely  
to Change the Way you Do Everything

Along with the rest of the 0.3 series, this release is still  
considered alpha quality software so it may not run all your apps or  
run on your hardware.

A detailed consolidation of all changes can be found in the changelog  
( ). A sum up  
of some of the more important changes is as follows:

     * Fixed inability to work with partitions bigger than 8Gb
     * Added possibility of installing into any of four primary  
     * Initial support for SerialATA controllers along with enhanced  
ATA support
     * Initial USB keyboards and mice support
     * Greatly improved network cards support (20 different NICs were  
tested successfully)
     * Increased stability in networking
     * A clone of MS paint application has been introduced
     * Initial support for MSVC compilation
     * Better cleanup of system resource usage
     * Synchronization of most of the Wine usermode DLLs and some  
Win32 subsystem code shared with Wine

Main news link:
Download link:

Aleksey Bragin
ReactOS Foundation President
Aleksey Bragin | 27 Apr 11:11 2009

ReactOS 0.3.9 Released

Our development team is pleased to announce the 9th increment of the  
0.3 series of ReactOS, an open source Windows® compatible operating  

As we draw ever closer to the 0.4 series, more and more work is being  
put into bugfixing existing code in an effort to get more  
applications and drivers working. This release is testament to that  
and is our most compatible release to date. However, the development  
team have still been working on expanding the features alongside  
bugfixing existing features, and quite a few additions have found  
their way into this release. Two key areas which stand out are the  
much improved network stack and the emergence of sound support in the  
kernel via the new kernel streaming services.

Along with the rest of the 0.3 series, this release is still  
considered alpha quality software so it may not run all your apps or  
run on your hardware.

A detailed consolidation of all changes can be found in the changelog  
( A sum up of  
some of the more important changes is as follows:

     * Reduced minimum memory requirement to 32Mb. In theory ReactOS  
can now be installed with 24Mb and run with only 20Mb
     * A new, faster Hyperspace Mapping Interface has been  
implemented in the kernel resulting in a speed improvement of over 300%
     * Security check improvements to the Object Manager in the  
kernel improves performance by 500%. Noticeable during large file/ 
registry operations
     * Various NDIS and AFD problems have been solved which increase  
compatibility with 3rd party NIC drivers and hardening of the network  
     * Preliminary support for sound via the new Kernel Streaming  
service. It's now possible to use the ac97 driver via our new Port  
Class library to play sound bytes using winamp
     * A great deal of work has been put into the command prompt to  
make it much more compatible. It's now able to run very complex  
scripts, including our own Build Environment
     * Many bugfixes to the kernel mode portion of the GDI resulting  
in much improved drawing engine across all bit depths
     * Synchronization of most of the Wine usermode DLLs

Main news link:
Download link:

Aleksey Bragin
ReactOS Foundation President