Radian is an enhanced interactive console for the GNU R statistical computing system. It provides rich syntax highlighting, multi-line editing, and auto-completion similarly to Python's IPython or Ruby's IRB. Radian may be a good middle ground for users that find vanilla R to be a bit too spartan but RStudio to be a bit too heavyweight. The Settings section provides an overview of the customizations supported by Radian. These include a number of color schemes for syntax highlighting, Emacs or vi key bindings, optional auto-indentation of code as it is entered, and a variety of options for customizing Radian's prompt. The Installation section lists requirements and provides setup instructions. Radian can be installed on Windows, macOS, and Linux systems. Radian is distributed under the MIT license, with source code available on GitHub.