Using async, if you want something to allow listeners to be attached later: var outcome = Boxon(); fs.readFile( "test.txt", outcome ); // Attach listener

Using async, if you want something to allow listeners to be attached later: var outcome = Boxon(); fs.readFile( "test.txt", outcome ); // Attach listener later: outcome( function( err, content ){ ... } ); See https://github.com/JeanHuguesRobert/l8/wiki/AboutBoxons https://github.com/JeanHuguesRobert/l8/wiki/AboutBoxons Boxon objects are light compared to promises, but they interop well. Best of both worlds!