These docs are written in Commonmark Markdown with a small bit of rST. We’ve chosen Markdown because it is easy to write. The docs are served in production at

If you want to build the documentation locally (e.g. to test your changes), the dependencies are automatically installed as part of Zulip development environment provisioning, and you can build the documentation using:

cd docs/
make html

and then opening file:///path/to/zulip/docs/_build/html/index.html in your browser (you can also use e.g. firefox docs/_build/html/index.html from the root of your Zulip checkout).

You can also usually test your changes by pushing a branch to GitHub and looking at the content on the GitHub web UI, since GitHub renders Markdown.

When editing dependencies for the Zulip documentation, you should edit requirements/docs.txt (which is used by ReadTheDocs to build the documentation quickly, without installing all of Zulip’s dependencies).