[24] In order to avoid copyright prosecution, ReactOS had to be expressly completely distinct and non-derivative from Windows, a goal that needed very careful work.

[29] On 27 January 2006, the developers responsible for maintaining the ReactOS code repository disabled access after a meeting was held to discuss the allegations.

Since ReactOS is a free and open-source software development project, the claim triggered a negative reaction from the free software community: in particular, Wine barred several inactive developers from providing contributions[citation needed] and formal high level cooperation between the two projects remained difficult as of 2006[update].

[30] In a statement on its website, ReactOS cited differing legal definitions of what constitutes clean-room reverse engineering as a cause for the conflict.

[32][33] ReactOS clarified its Intellectual Property Policy Statement requirements on clean room reverse engineering to avoid potential infringement of United States law.

[34] Also, the 2004 leaked Windows source code[35] was not seen as legal risk for ReactOS, as the trade secret was considered indefensible in court due to broad spread.

He suggests that the project took source code from the Windows Research Kernel, which was licensed to universities and has been leaked multiple times.

[50] The money went to ReactOS Deutschland e. V.. As the tax law in Germany for this form of a registered voluntary association (Eingetragener Verein) makes it problematic to pay developers directly;[51] indirect possibilities like stipends were evaluated.

[57][58] On 1 June 2014, the flexible crowdfunding campaign on Indiegogo ended, raising $25,141 for the development of the community edition,[59][60] and the voting process to support hardware and software was started shortly thereafter.

[114][115][116] Presently, ReactOS has active development in: Czech, English, Dutch, Finnish, French, German, Hebrew, Hungarian, Indonesian, Italian, Japanese, Mandarin Chinese, Norwegian, Polish, Russian, Spanish, Swedish, Thai, Ukrainian.

The project compiles using both MinGW and Microsoft Visual Studio, and contributes to the development of the build systems used through the submission of patches to its components.

[136] While Wine's NTDLL, USER32, KERNEL32, GDI32, and ADVAPI32 components cannot be used directly by ReactOS due to architectural differences, code snippets of them and other parts can be shared between both projects.

FreeType is an open-source software development library, used to render text on to bitmaps and provides support for other font-related operations.

[10] A 2004 article and interview of the German weekly magazine Der Spiegel describes ReactOS as directed at Windows users who want to renounce use of proprietary commercial software without having to switch to Linux.

[10] DistroWatch, a Linux distribution's monitoring Web site, also lists ReactOS and describes it as "a free and open-source operating system based on the best design principles found in the Windows NT architecture.

"[145] In his column for Free Software Magazine, David Sugar noted in 2006 that ReactOS would allow the use of applications depending on older versions of Windows whose APIs have been deprecated.

He also recognized its potential to expand the total deployed base of free software, and as a resource for developers wanting to know undocumented Windows APIs in the course of writing portable applications.

[12] PC Magazine columnist John C. Dvorak remarked in 2008 that the Windows NT architecture had remained largely unchanged, making it an ideal candidate for cloning, and believed that ReactOS could be "a bigger threat than Linux to Microsoft's dominance".

[11] In response to Dvorak's column, ZDNet technology journalist Dana Blankenhorn noted in 2008 that a lack of corporate sponsors and partners had rendered the project harmless to Microsoft.

[149] In August 2018, Jesse Smith from DistroWatch Weekly reviewed ReactOS v0.4.9, reporting that it suffered from limited hardware support and that it tended to lock up under load.

He concluded: "[it] should be used with caution and probably not as a main, day-to-day operating system"[150] The ReactOS Project won on the annual Seliger Youth Forum "The Best Presentation" award with 100,000 Russian rubles ($2700) in 2011, attended by Alexander Rechitskiy, one of the development team members.