ReactOS Weekend: A Fork Runs Gemma 4, Its Desktop Lands on Linux, and a Modified UDFS Driver Gets Benchmarked

It was a busy weekend for ReactOS, the open-source operating system that aims to run Windows apps and drivers. One fork ran a local AI model, another project put the ReactOS desktop on Linux, a nightly build ran Apple IIgs demos, and a driver developer posted disk benchmarks. All four come from community X posts, which we checked against project pages and the screenshots themselves.

Disclosure: VetTV develops VetTV Retro OS, a fork of ReactOS that is still in development.

CusDeb OS Alpha 1: the ReactOS desktop on a Linux kernel

Russian Linux news site OpenNET reported (X post) on Oct. 25 that the project formerly called C:\Deb has released its first alpha under a new name, CusDeb OS. According to the project page, Alpha 1 runs on Debian 13 with Wine 11.19 and CDEX 0.0.13. CDEX is the project’s desktop environment, built from the ReactOS shell and modified to run without the ReactOS kernel. It’s a live system of about 894 MB that can be installed to a drive from the live session. OpenNET names Debian package maintainer Evgeny Golyshev as the author.

The goals for Alpha 2, per OpenNET and the project page, are a native 64-bit CDEX (Alpha 1 runs 32-bit CDEX on 64-bit Linux), Direct3D 3-11 through D7VK and DXVK, and a move from Xorg to Wayland. OpenNET also says the developers want CusDeb to be a full Windows 10 alternative within a year. Analysis: That’s an ambitious goal for an alpha. In OpenNET’s comments, a user posting as the developer said Alpha 1 still uses the stock ReactOS branding, and rebranding is planned for Alpha 2.

LiberNT runs Gemma 4 locally with llama.cpp

On Oct. 24, @PromptInjection posted a screenshot of llama.cpp running Google’s Gemma 4 “natively” on LiberNT “with a few patches.” LiberNT is a GPL-3.0 fork of ReactOS that targets Windows 11 (NT10) compatibility on amd64, arm64 and riscv64. Its builds are labeled debug pre-releases for testing only.

Here’s what the screenshot shows:

• The About LiberNT dialog reports version 0.4.17-amd64-dev (20261023-6d0f316), identifying as NT 10.0 build 26100.
• The model file is gemma-4-E2B-it in GGUF format.
• A llama-server console window is open.
• A chat UI at 127.0.0.1 shows generation speeds of roughly 15-16 tokens per second, with one reply at 32.70 t/s.

Gemma 4 E2B is the smallest model in the family, with 2.3B effective parameters according to Google’s model card. Google documents running it with llama.cpp. The poster didn’t say what hardware was used or what the patches change, so the speeds can’t be compared to anything.

A ReactOS 0.4.17 nightly runs Apple IIgs demos from NTFS

@thebelovedmoon posted on Oct. 26 that they had loaded the “Modulae” and “Xmas” demos in ActiveGS 3.7.1019 beta, an Apple IIgs emulator, on a ReactOS 0.4.17-x86-dev nightly, “on an ntfs-formatted drive, no less.” The VM runs in UTM/QEMU on an Apple Silicon Mac. The screenshot shows build 20261024-0.4.17-dev-1230-g208bb7f. The post quotes a 2022 test showing ActiveGS working on ReactOS 0.4.15-dev.

Context: The current stable ReactOS release is still 0.4.16 from Aug. 29. 0.4.17 exists only as nightly builds, which ReactOS says are more likely to have regressions.

The ReactOS UDFS driver vs. Windows 7 NTFS

Bryan Kirk (@Zero3K) posted a CrystalDiskMark 8.0.6 comparison on Oct. 25. It pits Windows 7’s NTFS driver against a UDF 2.50 volume using his modified ReactOS UDFS driver, both running on Windows 7 (build 7601, Test Mode). The figures below are from his screenshot (5 runs, 1 GiB, MB/s):

Test	NTFS read	NTFS write	UDFS read	UDFS write
SEQ1M Q8T1	1053.26	899.35	979.54	935.29
SEQ1M Q1T1	1057.17	929.92	970.54	887.06
RND4K Q32T1	54.54	55.35	54.96	40.26
RND4K Q1T1	50.11	42.00	47.47	41.64

Analysis: The UDFS driver comes close to NTFS in sequential tests and in most random tests. The biggest gap is in deep-queue random writes. However, the two tests ran on different volumes (C: at 70% full and an empty F:), so this is a rough comparison, not a controlled test. In an Oct. 17 post, Kirk said the driver can now read and write UDF 2.50, can be chosen as a format option in ReactOS setup, and can boot. We couldn’t confirm whether that work has been merged into ReactOS master.

The takeaway

Opinion: ReactOS itself moves slowly, but the projects built on it are moving fast. A fork running a modern local AI model and a Linux distro borrowing the ReactOS shell both suggest the codebase is useful beyond the main project. VetTV News hasn’t tested any of these builds.

Sources

• OpenNET: CusDeb OS alpha (Oct. 25, 2026)
• @opennetru on X
• CusDeb OS project page
• cusdeb-com/os on GitHub
• @PromptInjection on X (Oct. 24)
• LiberNT on GitHub
• Google: Run Gemma with llama.cpp
• Google: Gemma 4 E2B model card
• @thebelovedmoon on X (Oct. 26)
• ReactOS 0.4.16 release notes
• ReactOS downloads and nightlies
• @Zero3K benchmark (Oct. 25)
• @Zero3K UDFS update (Oct. 17)