The macro_railroad Chrome extension is a powerful tool for generating syntax diagrams for Rust macros. Developed by Lukas Lueg, this free extension is perfect for developers looking to visualize the syntax of macros generated by `rustdoc`.

With macro_railroad, the syntax diagrams are conveniently displayed beneath each macro-block, making it easy to understand and analyze the structure of the macros. The extension also provides icons in the lower right corner for controlling options and expanding the diagrams to fullscreen.

One notable feature of this extension is its ability to access local documentation through the `file:///*` permission. This ensures that developers can generate syntax diagrams for macros even when working with local documentation. Rest assured, no data is ever transferred through this extension.

For those interested in contributing or exploring the inner workings of macro_railroad, the extension is open source and welcomes contributions on its GitHub repository.