zulip/docs/subsystems/documentation.md

# Documentation systems

Zulip has three major documentation systems:

* Developer and sysadmin documentation: Documentation for people
  actually interacting with the Zulip codebase (either by developing
  it or installing it), and written in Markdown.

* Core website documentation: Complete webpages for complex topics,
  written in HTML, JavaScript, and CSS (using the Django templating
  system).  These roughly correspond to the documentation someone
  might look at when deciding whether to use Zulip.  We don't expect
  to ever have more than about 10 pages written using this system.

* General user documentation: Our scalable system for documenting
  Zulip's huge collection of specific features without a lot of
  overhead or duplicated code/syntax, written in Markdown.  We expect
  to eventually have around 100 pages written using this system.  The
  target audience for this system is individual Zulip users.

These three systems are documented in detail.

## Developer and sysadmin documentation

What you are reading right now is part of the collection of
documentation targeted at developers and people running their own
Zulip servers.  These docs are written in
[Commonmark Markdown](http://commonmark.org/) with a small bit of rST.
We've chosen Markdown because it is
[easy to write](http://commonmark.org/help).  The source for Zulip's
developer documentation is at `docs/` in the Zulip git repository, and
they are served in production at
[zulip.readthedocs.io](https://zulip.readthedocs.io/en/latest/).

If you want to build the developer 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:

```
./tools/build-docs
```

and then opening `http://127.0.0.1:9991/docs/index.html` in your
browser.  The raw files are available at
`file:///path/to/zulip/docs/_build/html/index.html` in your browser
(so you can also use e.g. `firefox docs/_build/html/index.html` from
the root of your Zulip checkout).

If you are adding a new page to the table of contents, you will want
to modify `docs/index.rst` and run `make clean` before `make html`, so
that other docs besides your new one also get the new entry in the
table of contents.

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, though that won't be as faithful as the `make html`
approach.

When editing dependencies for the Zulip documentation, you should edit
`requirements/docs.in` and then run `tools/update-locked-requirements`
which updates docs.txt file (which is used by ReadTheDocs to build the
Zulip developer documentation, without installing all of Zulip's
dependencies).

## Core website documentation

Zulip has around 10 HTML documentation pages under `templates/zerver`
for specific major topics, like the features list, client apps,
integrations, hotkeys, API bindings, etc.  These documents often have
somewhat complex HTML and JavaScript, without a great deal of common
pattern between them other than inheriting from the `portico.html`
template.  We generally avoid adding new pages to this collection
unless there's a good reason, but we don't intend to migrate them,
either, since this system gives us the flexibility to express these
important elements of the product clearly.

## General user documentation

To learn more about Zulip's general user documentation, visit our guide
on writing user documentation [here](user-docs.html).