jazzy

Jazzy is a command-line tool that reads your Swift or Objective-C source code and generates a documentation website from it. Instead of just scanning plain text files, it hooks into the same internal tools that Apple's Xcode editor uses to understand code structure, which means the output is more accurate. The generated pages are styled to match how Apple presents its own official API reference documentation.

You install it like any Ruby tool (via the gem install jazzy command) and then run it from the folder containing your Apple platform project. For straightforward projects, running the command without any arguments is often enough. For more complex setups, there are many options: you can tell it which module to document, pass extra build flags to Xcode, configure an author name and website, and specify where the output should be saved. All these options can also be written into a configuration file called .jazzy.yaml so you do not have to type them every time.

The tool supports writing documentation comments in the standard Apple style, using markdown-formatted text and special keywords like parameter descriptions and return value explanations. These comments appear in the generated pages alongside the relevant class, method, or property. Jazzy also supports linking between symbols within the documentation, so clicking a type name in one article can take you directly to that type's reference page. Math equations written in LaTeX format can be embedded in documentation and will render as formatted equations in the output.

For teams documenting more than one module at once, there is a configuration option to generate a single unified documentation site covering all of them. The tool can document both source code projects and pre-compiled Swift framework files. It runs on macOS, where Apple's developer tools are natively available, with limited support for Linux noted separately in the README.

Jazzy is a mature tool from the Realm team and is well suited for Apple platform library authors who want to publish clean, browsable API reference docs.