```

#### Virtualenv with pip

```sh
source activate myenv
pip install ipykernel
python -m ipykernel install --user --name myenv --display-name "Python (myenv)"
```

### R (Ark Kernel) {#r-ark}

Install [Ark](https://github.com/posit-dev/ark/releases) by downloading the release for your operating system. For example, for macOS just unpack `ark` binary and put it into `/usr/local/bin`. Then run:

```sh
ark --install
```

### R (Xeus Kernel) {#r-xeus}

- Install [Xeus-R](https://github.com/jupyter-xeus/xeus-r)
- Install the R Extension for Zed (search for `R` in Zed Extensions)

<!--
TBD: Improve R REPL (Ark Kernel) instructions
-->

### Typescript: Deno {#typescript-deno}

- [Install Deno](https://docs.deno.com/runtime/manual/getting_started/installation/) and then install the Deno jupyter kernel:

```sh
deno jupyter --install
```

<!--
TBD: Improve R REPL (Ark Kernel) instructions
-->

### Julia

- Download and install Julia from the [official website](https://julialang.org/downloads/).
- Install the Julia Extension for Zed (search for `Julia` in Zed Extensions)

<!--
TBD: Improve Julia REPL instructions
-->

### Scala

- [Install Scala](https://www.scala-lang.org/download/) with `cs setup` (Coursier):
  - `brew install coursier/formulas/coursier && cs setup`
- REPL (Almond) [setup instructions](https://almond.sh/docs/quick-start-install):
  - `brew install --cask temurin` (Eclipse foundation official OpenJDK binaries)
  - `brew install coursier/formulas/coursier && cs setup`
  - `coursier launch --use-bootstrap almond -- --install`

## Changing which kernel is used per language {#changing-kernels}

Zed automatically detects the available kernels on your system. If you need to configure a different default kernel for a
language, you can assign a kernel for any supported language in your `settings.json`.

```json
{
  "jupyter": {
    "kernel_selections": {
      "python": "conda-env",
      "typescript": "deno",
      "javascript": "deno",
      "r": "ark"
    }
  }
}
```

## Debugging Kernelspecs

Available kernels are shown via the `repl: sessions` command. To refresh the kernels you can run, use the `repl: refresh kernelspecs` command.

If you have `jupyter` installed, you can run `jupyter kernelspec list` to see the available kernels.

```sh
$ jupyter kernelspec list
Available kernels:
  ark                   /Users/z/Library/Jupyter/kernels/ark
  conda-base            /Users/z/Library/Jupyter/kernels/conda-base
  deno                  /Users/z/Library/Jupyter/kernels/deno
  python-chatlab-dev    /Users/z/Library/Jupyter/kernels/python-chatlab-dev
  python3               /Users/z/Library/Jupyter/kernels/python3
  ruby                  /Users/z/Library/Jupyter/kernels/ruby
  rust                  /Users/z/Library/Jupyter/kernels/rust
```

> Note: Zed makes best effort usage of `sys.prefix` and `CONDA_PREFIX` to find kernels in Python environments. If you want explicitly control run `python -m ipykernel install --user --name myenv --display-name "Python (myenv)"` to install the kernel directly while in the environment.