The Mono Project (mono/mono) (‘original mono’) has been an important part of the .NET ecosystem since it was launched in 2001. Microsoft became the steward of the Mono Project when it acquired Xamarin in 2016.

The last major release of the Mono Project was in July 2019, with minor patch releases since that time. The last patch release was February 2024.

We are happy to announce that the WineHQ organization will be taking over as the stewards of the Mono Project upstream at wine-mono / Mono · GitLab (winehq.org). Source code in existing mono/mono and other repos will remain available, although repos may be archived. Binaries will remain available for up to four years.

Microsoft maintains a modern fork of Mono runtime in the dotnet/runtime repo and has been progressively moving workloads to that fork. That work is now complete, and we recommend that active Mono users and maintainers of Mono-based app frameworks migrate to .NET which includes work from this fork.

We want to recognize that the Mono Project was the first .NET implementation on Android, iOS, Linux, and other operating systems. The Mono Project was a trailblazer for the .NET platform across many operating systems. It helped make cross-platform .NET a reality and enabled .NET in many new places and we appreciate the work of those who came before us.

Thank you to all the Mono developers!

Download

Release channels: Nightly - Preview - Stable

Source code is available on GitHub (viewing only) or as a Tarball.

Please choose your operating system to view the available packages

Mono for macOS is available as a Mac Package (.pkg)

Please refer to the installation guide for more information about how to install and configure your Mono environment.

Download Mono

Supported on macOS 10.9 and later. Check the uninstall instructions if you want to remove Mono from your Mac.

Linux distribution

1 Add the Mono repository to your system

The package repository hosts the packages you need, add it with the following commands.

Note: the packages should work on newer Ubuntu versions too but we only test the ones listed below.

Ubuntu 20.04 (amd64, armhf, arm64, ppc64el)

sudo apt install ca-certificates gnupg
sudo gpg --homedir /tmp --no-default-keyring --keyring /usr/share/keyrings/mono-official-archive-keyring.gpg --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 3FA7E0328081BFF6A14DA29AA6A19B38D3D831EF
echo "deb [signed-by=/usr/share/keyrings/mono-official-archive-keyring.gpg] https://download.mono-project.com/repo/ubuntu nightly-focal main" | sudo tee /etc/apt/sources.list.d/mono-official-nightly.list
echo "deb [signed-by=/usr/share/keyrings/mono-official-archive-keyring.gpg] https://download.mono-project.com/repo/ubuntu preview-focal main" | sudo tee /etc/apt/sources.list.d/mono-official-preview.list
sudo apt update

Ubuntu 18.04 (i386, amd64, armhf, arm64, ppc64el)

sudo apt install ca-certificates gnupg
sudo gpg --homedir /tmp --no-default-keyring --keyring /usr/share/keyrings/mono-official-archive-keyring.gpg --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 3FA7E0328081BFF6A14DA29AA6A19B38D3D831EF
echo "deb [signed-by=/usr/share/keyrings/mono-official-archive-keyring.gpg] https://download.mono-project.com/repo/ubuntu nightly-bionic main" | sudo tee /etc/apt/sources.list.d/mono-official-nightly.list
echo "deb [signed-by=/usr/share/keyrings/mono-official-archive-keyring.gpg] https://download.mono-project.com/repo/ubuntu preview-bionic main" | sudo tee /etc/apt/sources.list.d/mono-official-preview.list
sudo apt update

Ubuntu 16.04 (i386, amd64, armhf, arm64, ppc64el)

sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 3FA7E0328081BFF6A14DA29AA6A19B38D3D831EF
sudo apt install apt-transport-https ca-certificates
echo "deb https://download.mono-project.com/repo/ubuntu nightly-xenial main" | sudo tee /etc/apt/sources.list.d/mono-official-nightly.list
echo "deb https://download.mono-project.com/repo/ubuntu preview-xenial main" | sudo tee /etc/apt/sources.list.d/mono-official-preview.list
sudo apt update

2 Install Mono 

sudo apt install mono-devel

The package mono-devel should be installed to compile code.

The package mono-llvm-support should be installed for LLVM JIT/AOT support. See here for more about LLVM Mono.

The package mono-complete should be installed to install everything - this should cover most cases of "assembly not found" errors.

The package mono-dbg should be installed to get debugging symbols for framework libraries - allowing you to get line numbers in stack traces.

The package referenceassemblies-pcl should be installed for PCL compilation support - this will resolve most cases of "Framework not installed: .NETPortable" errors during software compilation.

The package ca-certificates-mono should be installed to get SSL certificates for HTTPS connections. Install this package if you run into trouble making HTTPS connections.

The package mono-xsp4 should be installed for running ASP.NET applications.

3 Verify Installation

After the installation completed successfully, it's a good idea to run through the basic hello world examples on this page to verify Mono is working correctly.

Notes

Mono on Linux before 3.12 by default didn't trust any SSL certificates so you got errors when accessing HTTPS resources. This is not required anymore as 3.12 and later include a new tool that runs on package installation and syncs Mono's certificate store with the system certificate store (on older versions you had to import Mozilla's list of trusted certificates by running mozroots --import --sync). Some systems are configured in a way so that the necessary package isn't pulled in when Mono is installed, in those cases make sure the ca-certificates-mono package is installed.

1 Add the Mono repository to your system

The package repository hosts the packages you need, add it with the following commands.

Note: the packages should work on newer Debian versions too but we only test the ones listed below.

Debian 10 (i386, amd64, armhf, arm64, armel, ppc64el)

sudo apt install dirmngr ca-certificates gnupg
sudo gpg --homedir /tmp --no-default-keyring --keyring /usr/share/keyrings/mono-official-archive-keyring.gpg --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 3FA7E0328081BFF6A14DA29AA6A19B38D3D831EF
echo "deb [signed-by=/usr/share/keyrings/mono-official-archive-keyring.gpg] https://download.mono-project.com/repo/debian nightly-buster main" | sudo tee /etc/apt/sources.list.d/mono-official-nightly.list
echo "deb [signed-by=/usr/share/keyrings/mono-official-archive-keyring.gpg] https://download.mono-project.com/repo/debian preview-buster main" | sudo tee /etc/apt/sources.list.d/mono-official-preview.list
sudo apt update

2 Install Mono 

sudo apt install mono-devel

The package mono-devel should be installed to compile code.

The package mono-llvm-support should be installed for LLVM JIT/AOT support. See here for more about LLVM Mono.

The package mono-complete should be installed to install everything - this should cover most cases of "assembly not found" errors.

The package mono-dbg should be installed to get debugging symbols for framework libraries - allowing you to get line numbers in stack traces.

The package referenceassemblies-pcl should be installed for PCL compilation support - this will resolve most cases of "Framework not installed: .NETPortable" errors during software compilation.

The package ca-certificates-mono should be installed to get SSL certificates for HTTPS connections. Install this package if you run into trouble making HTTPS connections.

The package mono-xsp4 should be installed for running ASP.NET applications.

3 Verify Installation

After the installation completed successfully, it's a good idea to run through the basic hello world examples on this page to verify Mono is working correctly.

Notes

Mono on Linux before 3.12 by default didn't trust any SSL certificates so you got errors when accessing HTTPS resources. This is not required anymore as 3.12 and later include a new tool that runs on package installation and syncs Mono's certificate store with the system certificate store (on older versions you had to import Mozilla's list of trusted certificates by running mozroots --import --sync). Some systems are configured in a way so that the necessary package isn't pulled in when Mono is installed, in those cases make sure the ca-certificates-mono package is installed.

1 Add the Mono repository to your system

The package repository hosts the packages you need, add it with the following commands.

Note: the packages should work on newer Raspbian versions too but we only test the ones listed below.

Raspbian 10 (armhf)

sudo apt install dirmngr ca-certificates gnupg
sudo gpg --homedir /tmp --no-default-keyring --keyring /usr/share/keyrings/mono-official-archive-keyring.gpg --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 3FA7E0328081BFF6A14DA29AA6A19B38D3D831EF
echo "deb [signed-by=/usr/share/keyrings/mono-official-archive-keyring.gpg] https://download.mono-project.com/repo/debian nightly-raspbianbuster main" | sudo tee /etc/apt/sources.list.d/mono-official-nightly.list
echo "deb [signed-by=/usr/share/keyrings/mono-official-archive-keyring.gpg] https://download.mono-project.com/repo/debian preview-raspbianbuster main" | sudo tee /etc/apt/sources.list.d/mono-official-preview.list
sudo apt update

2 Install Mono 

sudo apt install mono-devel

The package mono-devel should be installed to compile code.

The package mono-llvm-support should be installed for LLVM JIT/AOT support. See here for more about LLVM Mono.

The package mono-complete should be installed to install everything - this should cover most cases of "assembly not found" errors.

The package mono-dbg should be installed to get debugging symbols for framework libraries - allowing you to get line numbers in stack traces.

The package referenceassemblies-pcl should be installed for PCL compilation support - this will resolve most cases of "Framework not installed: .NETPortable" errors during software compilation.

The package ca-certificates-mono should be installed to get SSL certificates for HTTPS connections. Install this package if you run into trouble making HTTPS connections.

The package mono-xsp4 should be installed for running ASP.NET applications.

3 Verify Installation

After the installation completed successfully, it's a good idea to run through the basic hello world examples on this page to verify Mono is working correctly.

Notes

Mono on Linux before 3.12 by default didn't trust any SSL certificates so you got errors when accessing HTTPS resources. This is not required anymore as 3.12 and later include a new tool that runs on package installation and syncs Mono's certificate store with the system certificate store (on older versions you had to import Mozilla's list of trusted certificates by running mozroots --import --sync). Some systems are configured in a way so that the necessary package isn't pulled in when Mono is installed, in those cases make sure the ca-certificates-mono package is installed.

Mono for Windows is available as a Windows Installer file

Please refer to the installation guide for more information about how to install and configure your Mono environment.

Supported on Windows 7, 8, 10 or later.

Release Notes

Check out the release notes of all Mono versions on the releases page.

MonoDevelop IDE

Please visit the MonoDevelop website for more details about our cross-platform IDE.

Older releases

To access older Mono releases for macOS and Windows, check the archive on the download server. For Linux, please check the "Accessing older releases" section in the installation guide.