Rumen8

Parallels Desktop for Mac allows you to run Windows in a virtual machine on a Mac with an Intel CPU. This option is not free as you need to purchase a copy of Parallels Desktop, but there is a free two week trial period to see if this option suits you.
It does allow you to switch quickly back and forth between the Mac and Windows operating systems so is a very flexible setup.

VMware Fusion Player also allows you to run Windows in a virtual machine on a Mac with an Intel CPU. However, it can be a much less expensive option as VMware Fusion Player is now free for personal use. You will still need a copy of Windows 10 or 11. In the same manner as Parallels, you can switch quickly between the Mac and Windows operating systems so it is also very flexible setup.

VirtualBox is a free open source virtual machine for the Mac that will enable you to run Windows at the same time as MacOS on an Intel based computer. While not as fast as Fusion or Parallels and missing some of the more advanced features, it costs nothing and is suitable for Rumen8. It still requires a copy of Windows.
Step by step instructions on how to install Windows 10 in Virtualbox on a Mac are available here.

Apple's Bootcamp software also requires a licensed copy of Windows. You choose whether to boot into MacOS or Windows when you start your computer. Bootcamp comes with all Intel based Macs and is easy to setup, just look in the Utilities folder to start. Bootcamp setups are not as flexible as virtual machines as you only have access to one operating system at a time, but because Windows is not virtualised it runs at full speed.

Microsoft Windows 10 is available free as an ISO image suitable for installing in a virtual machine from from this Microsoft website. You can install Windows without providing a Product ID and run it for 30 days without activation. At this point it will still be usable with some minor functions disabled and nag you about activation occasionally, but will still be able to run Rumen8.

Microsoft Windows 11 is available free as an ISO image suitable for installing in a virtual machine from from this Microsoft website. You can install Windows without providing a Product ID and run it for 30 days without activation. At this point it will still be usable with some minor functions disabled and nag you about activation occasionally, but will still be able to run Rumen8.

VMWare Fusion allows you to run Windows 11 for arm on an Apple Silicon Mac and it has a free version for personal use that will be suitable for most people wanting to run Rumen8. As there is now a simplified setup process that downloads and installs Windows this is the recommended method to use Rumen8 on an Apple Silicon Mac. There is a video tutorial by Andrew Tsai here that walks you through installing Fusion and Windows so you can then install and use Rumen8.
Once setup is complete you can then switch quickly back and forth between the Mac and Windows operating systems so is a very flexible setup.
Rumen8 is not native to the ARM architecture so must be run in an emulator provided by Windows 11. This means it will not run as quickly as on an Intel Mac.

Parallels Desktop for Mac allows you to run Windows 11 for ARM in a virtual machine on an Apple Silicon Mac. This option is not free as you need to purchase Parallels but is very simple to set up and use. Using Parallels to run Windows is supported by Microsoft so if you plan to use it for more than Rumen8 it may be worth considering. A free two week trial is available to see if this option suits you.
Setup is extremely simple with Parallels Desktop automatically downloading and installing Windows 11. You can then switch quickly back and forth between the Mac and Windows operating systems so is a very flexible setup.
Rumen8 is not native to the ARM architecture so must be run in an emulator provided by Windows 11. This means it will not run as quickly as on an Intel Mac.

Microsoft Windows 11 for ARM is available free and is now officially supported by Microsoft on a Apple Silicon Mac using Parallels. You can install Windows without providing a Product ID and run it for 30 days without activation. At this point it will still be usable with some minor functions disabled and nag you about activation occasionally, but will still be able to run Rumen8.