.NET Virtual Environment, or dotnet-venv for short, is a .NET tool that installs the specified .NET SDK into the specified directory and pins the version using a global.json file.

If you are familiar with Python venv, dotnet-venv works similarly by creating an isolated environment with its own .NET SDK version.

dotnet-venv allows you to quickly install a specific version of the .NET SDK into a directory for evaluation or testing. For example, if you want to try out a new .NET preview release without installing it machine-wide, dotnet-venv makes this easy.

If you have .NET 8.0 or .NET 9.0 SDK installed, you can install dotnet-venv as a .NET Tool.

Run the following command:

dotnet tool install dotnet-venv --global

If you do not have .NET 8.0 or .NET 9.0 SDK installed, or if you prefer to use the standalone executable, follow the following steps:

1. Head to the Releases page.
2. Download the latest release suitable for your operating system.
3. Extract the downloaded file to a directory of your choice.
4. Add the directory, which dotnet-venv is in, to the PATH environment variable.

USAGE:
    dotnet-venv [OPTIONS]

OPTIONS:
    -h, --help                 Print help information.
    -n, --name <ENV_DIR>       The directory to create the virtual environment in. The default is a directory named .net inside the current directory.
        --no-logo              Suppress the application logo.
    -r, --release <RELEASE>    The .NET SDK release to install. Can be STS, LTS, or Preview, or a 2-part or 3-part version, such as 8.0, 9.0.200, or 10.0.100-preview.1.25120.13. The default is LTS.
    -v, --verbose              Enable verbose output.
        --version              Show the application version and exit.

To install and use the latest .NET 9.0 SDK in a directory called dotnet:

1. Run the following command, which will install the latest .NET 9.0 SDK, if it is not already installed on the machine:

   # On Windows (.NET Tool and standalone)
   dotnet-venv -n dotnet -r 9.0

   # On Linux and macOS (.NET Tool)
   dotnet-venv -n dotnet -r 9.0
   
   # On Linux and macOS (Standalone)
   ./dotnet-venv -n dotnet -r 9.0

2. Activate the virtual environment using the appropriate command for your operating system and terminal:

   # On Windows (PowerShell)
   .\dotnet\activate.ps1

   REM On Windows (Command Prompt)
   dotnet\activate.bat

   # On Linux and macOS
   source ./dotnet/activate

3. Use the .NET CLI as you normally would. For example:

   dotnet new console -n MyFancyProject

4. To deactivate the virtual environment, run:

   deactivate

Behind the scenes, dotnet-venv relies on:

• Releases Index JSON file to check the latest releases.
• dotnet-install scripts to install the .NET SDK.

If the specified .NET SDK is already installed, dotnet-venv will simply create a global.json file to pin the .NET SDK version. Otherwise, it will install the SDK into the specified directory.

When you activate the virtual environment, it adds the installation directory to the PATH environment variable, for the current terminal session, and prefixes the terminal prompt with the virtual environment name.

Activating a virtual environment relies on modifying the PATH environment variable for the current terminal session. If you launch your favourite IDE outside the context of this terminal session, it will not recognize the .NET SDK installed in the virtual environment.

If you are using Visual Studio Code, for example, after activating the virtual environment, start Visual Studio Code from the same terminal session with:

code .

Credit goes to Python venv for the idea. Additionally, the activation scripts are heavily inspired by those from Python venv.