It happens to be popular for server-side web development, but there's nothing inherent in it that forces you to use it for web.
Nothing web-related in this project, for example: https://github.com/neandrake/spirc
Nothing web-related in this project, for example: https://github.com/neandrake/spirc
Even if there are, I still feel that Javascript is too completely dependent on its position in web browsers for Node.js to be entirely disassociated with the web. If a new language would replace Javascript in the browser, Node.js would be instantly abandoned. But I could see your point.
Or npm (https://github.com/npm/npm), a package manager?
Npm uses Web protocols (HTTP, maybe JSON-RPC) to communicate with repository servers.
This is not saying that there aren't any non-web applications using Node.js, just that web-related applications using Node.js are quite numerous and popular.
Personally I know of Node.js applications and libraries targeting robotics, computer vision, language analysis, neural networks and more. Like any powerful platform, much of this relies on the ability of Node.js to interface with external libraries, which it does using wrappers built with node-gyp.
... except a several million line JIT