Intersphinx: Cross-reference other projects

Behind the built-in Sphinx extension intersphinx is a powerful tool to reference sections in other Sphinx and Jupyter Book documentation projects.

You can configure mappings to external Sphinx projects in your Jupyter Book configuration, the _config.yml file. In this example project, we have configured ebp to reference https://executablebooks.org/en/latest/. In the following code examples, we refer to the configured ebp mapping and link directly to a section called tools.

```{tab} MyST (Markdown)

We can link to pages in other documentation projects.
This is a link to the
[Executable Book project's list of tools they build](ebp:tools)

```{tab} reStructuredText


```{eval-rst}
We can link to pages in other documentation projects.
This is a link to the
:doc:`Executable Book project's list of tools they build <ebp:tools>`

In the above `reStructuredText` example, we use `{eval-rst}` to write reST inside a `.md` file (i.e. the one you are reading now). You only need to use this directive if you are writing reST code in a `.md` file.