Our CI environment provides multiple runtimes (e.g. Node.js or PHP versions), data stores and so on. Because of this, hosting your project on travis-ci.org means you can effortlessly test your library or applications against multiple runtimes and data stores without even having all of them installed locally.

An object essentially wraps up method dispatch and state

The Adapter, as implemented by the NodeAdapter and RackAdapter classes, exposes the Server’s interface over HTTP. It is responsible for serializing and deserialzing messages as JSON and accepting connections over various flavours of HTTP transport:

Persistent connections using WebSocket
Long-polling via HTTP POST
Cross Origin Resource Sharing
Callback-polling via JSON-P