How To Install Mono on Debian 11

In this tutorial, we will show you how to install Mono on Debian 11. For those of you who didn’t know, Mono is a free, open-source development platform based on the .NET Framework. Mono supports most modern operating systems with 32-bit and 64-bit architecture. A growing family of solutions and an active and enthusiastic contributing community helps position Mono to become the leading choice for the development of cross-platform applications.

This article assumes you have at least basic knowledge of Linux, know how to use the shell, and most importantly, you host your site on your own VPS. The installation is quite simple and assumes you are running in the root account, if not you may need to add ‘sudo‘ to the commands to get root privileges. I will show you the step-by-step installation of the Mono Framework on a Debian 11 (Bullseye).

Prerequisites

• A server running one of the following operating systems: Debian 11 (Bullseye).
• It’s recommended that you use a fresh OS install to prevent any potential issues.
• SSH access to the server (or just open Terminal if you’re on a desktop).
• A non-root sudo user or access to the root user. We recommend acting as a non-root sudo user, however, as you can harm your system if you’re not careful when acting as the root.

Install Mono on Debian 11 Bullseye

Step 1. Before we install any software, it’s important to make sure your system is up to date by running the following apt commands in the terminal:

sudo apt update
sudo apt upgrade
sudo apt install dirmngr gnupg apt-transport-https ca-certificates

Step 2. Installing Mono on Debian 11.

By default, Mono is available in Debian’s default repositories, Now we run the following command to add the Mono repository to your Debian system:

sudo sh -c 'echo "deb https://download.mono-project.com/repo/debian stable-buster main" > /etc/apt/sources.list.d/mono-official-stable.list'

Next, import the GPG key:

sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 3FA7E0328081BFF6A14DA29AA6A19B38D3D831EF

After that, update the packages list and install Mono, after the apt repository is enabled:

sudo apt updatesudo apt install mono-complete

Let’s check the installed Mono version using the following command below:

mono --version

Step 3. Create Mono Application.

Now we create a sample program to run with Mono. Create a hello.cs file and edit in your favorite text editor:

sudo nano hello.cs

Add the following file:

using System;

public class Hello
{
  public static void Main(string[] args)
  {
  Console.WriteLine ("Hello!");
  }
}

Save the file and close it. Then compile the code:

mono-csc hello.cs

Next, run the executable using the command below:

mono hello.exe

Output:

Hello!

Then, set the execute permission on the newly created executable file. After that run the program as the below commands:

chmod +x hello.exe
./hello.exe

Congratulations! You have successfully installed Mono. Thanks for using this tutorial for installing the latest version of the Mono Framework on Debian 11 Bullseye. For additional help or useful information, we recommend you check the official Mono website.