Getting Started (Legacy)


The MOSA project is available as a zip download or via git:

git clone


You will also need the following prerequisites:


Install any Visual Studio version 2019 or newer. All editions are supported including the fully-featured free Community Edition.

Note: The MOSA source code repository includes Qemu virtual emulator for Windows.

The CodeMaid Visual Studio Extension is strongly recommended for MOSA contributors.


Install Mono and Qemu.

The minimum supported version of Mono is 5.16.

If using the APT package manager you can use the following command to quickly set up QEMU and Mono:

sudo apt-get -y install mono-devel qemu qemu-system qemu-system-x86


Install Mono and Qemu.

Running on Windows

Double click on the Compile.bat script in the root directory to compile all the tools, sample kernels, and demos.

Next double click on the Launcher.bat script, which will bring up the MOSA Launcher Tool that can:

  • Compile the operating system

  • Create a virtual disk image, with the compiled binary and boot loader

  • Launch a virtual machine instance (using QEMU by default)

By default, the CoolWorld operating system demo is pre-selected. Click the Compile and Run button to compile and launch the demo.