httpconfig
The browser version of ifconfig. Back-end API can return JSON or JSONP depending on how the request is formatted (this front-end only asks for JSON, at the moment). Built with Dojo and NodeJS. GitHub repository can be found at https://github.com/greg5green/httpconfig.
Note: This project is quite old and hasn't been updated. But sometimes it's fun to still see Dojo code in the wild