[ReactOS](https://reactos.org/) is an open-source operating system meant to behave exactly like Windows XP, Windows Server 2003 and later versions of Windows.
In theory, it can run any software and work with any drivers developed for these older versions of Windows. Decades old software or pieces of equipments that no longer ship with drivers to run with the latest iterations of the Windows operating system may work with ReactOS.
In practice, it is still under heavy-development and may not work as expected.
Support for the more modern PCI-Express-enabled Q35 chipset, UEFI or other virtio-devices, which Phyllome OS favors, is still lacking in ReactOS. Performance of the display won't be optimal, resulting in screen tearing. More information can be found [here](/virt/guest/reactos).
> Porting new paravirtual devices to ReactOS would significantly improve the experience of running ReactOS inside Phyllome OS, and other virtualization solutions leveraging [paravirtual hardware](https://wiki.phyllo.me/e/en/virt/virtio). See [here](https://reactos.org/contributing/) on how you can contribute to ReactOS
* *[Clone]() the `legacy model` of virtual machine and, optionally, [rename]() it*
* *[Add the ISO file]() you just downloaded and [add a disk]() of at least 1GB using the Virtual Machine Manager*
> As of 2022, a full installation of ReactOS takes around 750Mb.
{.is-info}
* *[Power-on the virtual machine]()*
* *[Connect to the console]()*
* *Just as in the good ol' days, you need to press a key to start the installer. Notice the fact that an open firmware, [SeaBIOS](https://www.seabios.org/SeaBIOS), is able to boot an open-source NT-based kernel. A rare sight.*
* *The system language and local can be customized here. If you are satisfied with the default settings, press <kbd>ENTER</kbd> or click on "Next". Otherwise, please modify the settings.*
* *Here, you should not have to configure anything for ReactOS to have LAN and Internet access, through the newly supported `virtio-net` device. Press <kbd>ENTER</kbd> or click on "Next" to go to the next screen.*
* *If you wish to share files with other computers on your network, joining a Workgroup would be a first step. Press <kbd>ENTER</kbd> or click on "Next" to go to the next screen.*
* *The system will automatically open a session with the user you created (that is pretty clever, as there is no need to remember the password I already forgot :')). A few windows may open, prompting you to install some devices. Unless you know what you are doing, cancel these prompts to land on the pristine desktop.*
* *As already stated, support for the more modern PCI-Express-enabled Q35 chipset, UEFI or other virtio-devices is not yet there. You may still enjoy the ride, try to install these old software that has long been forgotten in a drawer or this decade old printer collecting dust, and that no operating system would dare to interact with anymore*
* [Official resource](https://reactos.org/wiki/QEMU) on running ReactOS with QEMU
* [Hardware support list](https://reactos.org/wiki/Supported_Hardware) for ReactOS
* [Git repository](https://github.com/hectorm/docker-qemu-reactos) providing a Docker image for the ReactOS operating system
* [Current effort](https://github.com/QubesOS/qubes-issues/issues/2809) to integrate ReactOS and QubesOS
* [GSoC 2018 project idea](https://reactos.org/wiki/Google_Summer_of_Code_2018_Ideas#Paravirtualization_Support) to port more paravirtualized devices to ReactOS
[^1]: Support for [UEFI](https://reactos.org/wiki/UEFI), and potentially OVMF, is under-way.
[^2]: See [here](https://doxygen.reactos.org/d1/dc8/virtio__types_8h.html#a5a27dcd221caab788e973f6964d84aa9) for the source code reference for `virtio-net`
