Simple standalone NodeJS REPL.

repl.js

// Simple embedded REPL
var repl = require("repl");

repl.start({
    prompt: "karma> ",
    input: process.stdin,
    output: process.stdout,
    eval: function(cmd, context, filename, callback) {
        // cmd comes thru as "(ls\n)", get back to original "ls"
        callback("You typed: " + cmd.substring(1, cmd.length-1).trim()); 
    },
    writer: function(object) {
        return String(object);
    }
});