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reactos
reactos
C2017–2026
reactos / reactos

reactos

A free Windows-compatible Operating System

32Distinct people
41Mentions
1Explicit recommenders
18.5KGitHub stars
REPOSITORY AT A GLANCE

What to know before exploring

What it is

A free Windows-compatible Operating System

GitHub

Where it is used

No documented product use was verified in the last source check.

What people are saying

This has been one of my favorite software projects to watch, because it's such an insanely monumental undertaking and moves so damn slowly. There were people working on this…

owenversteeg used a recommendation phrase. One indexed comment matches. This is a phrase match, not a verdict.

No classified warning is attached to this page. Read the discussions before treating silence as approval.

Also in these discussions

Mentioned in the same Hacker News threads. That is not proof they are substitutes.

This week on Hacker News

Nov 7–Nov 14 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/14/2026, 11:56:56 AM UTC.

No direct repository links were found in the indexed HN discussions over the past seven days. Older discussions are available below.

Mentions over time

HN mentions by year41 dated mentions

Observed mentions: 2017-09-05 15:56:37 UTC to 2026-02-25 21:55:12 UTC.

02462017-01-01 00:00:00 UTC to 2018-01-01 00:00:00 UTC (exclusive): 3 mentions; 1 submissions, 2 comments20172018-01-01 00:00:00 UTC to 2019-01-01 00:00:00 UTC (exclusive): 4 mentions; 1 submissions, 3 comments2019-01-01 00:00:00 UTC to 2020-01-01 00:00:00 UTC (exclusive): 2 mentions; 0 submissions, 2 comments2020-01-01 00:00:00 UTC to 2021-01-01 00:00:00 UTC (exclusive): 6 mentions; 0 submissions, 6 comments2021-01-01 00:00:00 UTC to 2022-01-01 00:00:00 UTC (exclusive): 3 mentions; 0 submissions, 3 comments20212022-01-01 00:00:00 UTC to 2023-01-01 00:00:00 UTC (exclusive): 7 mentions; 0 submissions, 7 comments2023-01-01 00:00:00 UTC to 2024-01-01 00:00:00 UTC (exclusive): 5 mentions; 1 submissions, 4 comments2024-01-01 00:00:00 UTC to 2025-01-01 00:00:00 UTC (exclusive): 5 mentions; 0 submissions, 5 comments2025-01-01 00:00:00 UTC to 2026-01-01 00:00:00 UTC (exclusive): 1 mentions; 0 submissions, 1 comments2026-01-01 00:00:00 UTC to 2027-01-01 00:00:00 UTC (exclusive): 5 mentions; 0 submissions, 5 comments. Incomplete calendar period.2026*

* An incomplete calendar period is marked with an outlined bar. Its count is not directly comparable with a full period.

Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.

View mention counts and date ranges
UTC ranges include their start and exclude their end. Select a period to filter the source evidence.
PeriodStart (UTC)End (exclusive, UTC)MentionsSubmissionsComments
20172017-01-01 00:00:00 UTC2018-01-01 00:00:00 UTC312
20182018-01-01 00:00:00 UTC2019-01-01 00:00:00 UTC413
20192019-01-01 00:00:00 UTC2020-01-01 00:00:00 UTC202
20202020-01-01 00:00:00 UTC2021-01-01 00:00:00 UTC606
20212021-01-01 00:00:00 UTC2022-01-01 00:00:00 UTC303
20222022-01-01 00:00:00 UTC2023-01-01 00:00:00 UTC707
20232023-01-01 00:00:00 UTC2024-01-01 00:00:00 UTC514
20242024-01-01 00:00:00 UTC2025-01-01 00:00:00 UTC505
20252025-01-01 00:00:00 UTC2026-01-01 00:00:00 UTC101
2026 (partial)2026-01-01 00:00:00 UTC2027-01-01 00:00:00 UTC505

What Hacker News says

41 sources
"Microsoft's GitHub is hosting the leaked source code (which probably got sucked into Copilot and every other AI under the sun as a result)." "However, I don't think copyright lawyers will care. «They're also committing a crime» doesn't mean you're free to do what you want. That applies especially in ReactOS vs MS, because if ReactOS succeeds, it will compete directly with Microsoft." And ReactOS uses GitHub Copilot: https://github.com/reactos/reactos/pull/8516 There's also such thing as being responsible (for an outcome), which in case of litigation means being culpable. Microsoft here is the sole actor that has any control on the GitHub Copilot, on what it was fed with, and thus - on its output (which would be the base of their accusation if they sue). How do you imagine such a case could be made to look like it would have any legal sta
Read the rest
nding?
In 30 Years of ReactOS
"Assuming a ReactOS developer used Microsoft / Github Copilot to work on this codebase" No need to assume. It's a certainty: https://github.com/reactos/reactos/pull/8516 "if Microsoft attempts to sue (themselves?) over their own Copilot tool injecting their own copyrighted code into a user's codebase" Such an attempt can't make sense, given that the model used by ReactOS is in Microsoft's control and thus Microsoft alone is the one responsible for the model's behavior. They won't sue, thus much is clear.
In 30 Years of ReactOS
Well, it's not Claude, it's GitHub Copilot (which happens to be owned by none other than... guess who): https://github.com/reactos/reactos/pull/8516 But, if any such model got fed with leaked code, then how is this a specific open-source project's problem and not of all projects (either open-source or private) that got to ever use that model? Then, (having thought this just now) how can an argument relying on (legally) undisclosed information be used against anything public? Isn't the onus on the party having the undisclosed information to prove that it preceded the public one? How can that precedence be trusted by an independent judging party if the undisclosed information (source-code and systems managing that source code) is and always has been in the hands of the accusing (thus biased) party?
In 30 Years of ReactOS
This isn't really my arena, but I did happen to recently compare the implementation of ReactOS's RTL (Run Time Library) path routines [0] with Wine's implementation [1]. ReactOS covers a lot more of the Windows API than Wine does (3x the line count and defines a lot more routines like 'RtlDoesFileExists_UstrEx'). Now, this is not supposed to be a public API and should only be used by Windows internally, as I understand it. But it is an example of where ReactOS covers a lot more API than Wine does or probably ever will, by design. To whom (if anyone) this matters, I'm not sure. [0] https://github.com/reactos/reactos/blob/master/sdk/lib/rtl/p... [1] https://github.com/wine-mirror/wine/blob/master/dlls/ntdll/p...
In 30 Years of ReactOS
It goes beyond one-liners. This is especially apparent in sysres.c, where not only are the function names identical, they appear in the same order. There's also non-trivial functions, that are obviously copied line-by-line, with some modifications. See KepGetSystemResource for example. While I guess there's no proof that WinuxOS and ExectOS share the same authors (aside from identical first and last name), this ReactOS pull request was certainly done by the same person: https://github.com/reactos/reactos/pull/2853#issuecomment-65...
In ExectOS – brand new operating system which derives from NT architecture
There're worse issues actually. This person tried to commit to ReactOS repository, and then the PR blocked when the code is allegedly detected as Windows Research Kernel code: https://github.com/reactos/reactos/pull/2853#issuecomment-65... The decision may or may not be correct though as ReactOS maintainers can be paranoid for the first commits of new devs. Mostly, people play with IDA and try to write some code for a small portion, which is against the project's philosophy.
In ExectOS – brand new operating system which derives from NT architecture
This codebase bears striking resemblance to Minoca, another (much further along) NT-inspired kernel (https://github.com/minoca/os). There are strong structural similarities in the source tree and there are also source files that seem completely copypasted with comments changed and function contents gutted (such as ke/sysres.c, ke/runlevel.c, among others). Are you one of the Minoca developers working on a new project or are you defrauding Hacker News for attention? Edit: This same poster (Rafal "Belliash" Kupiec) has been noted for other plagiarism incidents going back to 2005: https://github.com/reactos/reactos/pull/2853#issuecomment-65... https://lists.reactos.org/hyperkitty/list/ros-dev@reactos.or...
In ExectOS – brand new operating system which derives from NT architecture
ReactOS is sometimes very disappointing. Take the issue with toolbar icons, for example. Toolbar icons in at least Office 97, Office 2000 and Visual Basic 6 were affected, as was some game [0]. Microsoft Office is a complex Win32 application, making it a good guinea pig for testing compatibility. And yet, this was fixed a few months ago, and the Office bug was reported in 2016 [1]. The bug with no text wrapping for tray balloons is also an embarrassing thing to have lingering for years (I assume it was like this since the balloons were first implemented in ReactOS). Does the world really need a buggy Windows Server 2003 reimplementation? I think the efforts of the development team could be better spent elsewhere. [0]: https://github.com/reactos/reactos/pull/5227 [1]: https://jira.reactos.org/browse/CORE-12377
In ReactOS Newsletter 103 – Late 2023 News
I think the problem here is that ReactOS wants to keep Windows compatibility. Don't forget ReactOS started out as an NT5 clone; I doubt porting Windows XP's NTLDR to UEFI would be as trivial as you may think it is. The source code for the bootloader doesn't seem all that complicated: https://github.com/reactos/reactos/tree/master/boot/freeldr Basic support seems to be finished, but there are still a few open tasks regarding EFI support: https://jira.reactos.org/browse/CORE-9841?jql=labels%20%3D%2.... Based on https://jira.reactos.org/browse/CORE-16175, I think the project is using Microsoft's bootloader to load the ReactOS kernel during the testing phase. If that's the level of compatibility they're going for, I can imagine implementing full UEFI support will take ages.
In ReactOS Newsletter 103 – Late 2023 News
A quick test-run on the pages linked from the hackernews front page: hackernews svg logo doesn't render youtube embed on the servo homepage doesn't load https://github.com/tpope/timl -> reloads/rerenders infinitely, uses 100% of 1 core https://akrzemi1.wordpress.com/2023/04/23/the-obvious-final-... -> hangs while loading the page, uses 100% of 1 core https://equalitytime.github.io/FlowersForTuring/ -> loads/renders fine https://github.com/reactos/reactos -> reloads/rerenders infinitely, uses 100% of 1 core https://dolphin-emu.org/blog/2023/05/27/dolphin-steam-indefi... -> loads fine but css rendering/placement is off on breadcrumbs and article https://xcp-ng.org/blog/2023/05/23/new-xen-updates-on-risc-v... -> very long load then hangs while loading javascript/content. Not a great batting average - seems like sites need to be purpose built
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for this or leverage little/no modern javascript libraries for it to render accurately. Servo has been in this state for the last 5 or 6 years since I first discovered it.
In Servo, the parallel browser engine written in Rust

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