> io.js is an npm compatible platform originally based on node.js
It's not a library, it's a platform that's based on node.js. It's more or less a fork of node or "spork" as they call it.
The github repo is a bit more clear: https://github.com/iojs/io.js
The main point seems to be that it's run on an open governance model: https://github.com/iojs/io.js/blob/v1.x/GOVERNANCE.md
"io.js is an api-compatible alternative to the node.js runtime, including support for the npm ecosystem, that aims to release faster than the node.js release cycle and move according to a community-driven open governance model."
Given the tremendous volume of packages released to npm, the current one-liner initially just doesn't convey much information. In context of the comments here, it all parses perfectly, but I was one of many who needed this context to understand the (apparent) goals of the project.
Ya, I think the main problem is that no one has any idea what that means from a practical sense. Will my code go faster? Will I get better support? etc.