function Async() {
	return {
		bind: bind,
		parallel: parallel,
		run: run,
		sequence: sequence,
		wait: wait,
		wrap: wrap
	};

	function bind(m, f) {
		return function(g) {
			m(function(x) {
				f(x)(g);
			});
		}
	}

	function parallel() {
		var threads = arguments;
		var pending = threads.length;
		var results = [];
		return function(f) {
			var useResult = function(i) {
				return function(x) {
					results[i] = x;
					pending--;
					if(pending < 1) {
						f(results);
					}
				};
			};
			for(var i = 0; i < threads.length; i++) {
				threads[i](useResult(i));
			}
		};
	}

	function run() {
		var m;
		if(arguments.length == 1) {
			m = arguments[0];
		} else {
			m = sequence.apply(null, arguments);
		}
		m(function() {});
	}

	function sequence() {
		var steps = arguments;
		var i = 0;
		return function(f) {
			var step = function() {
				if(i < steps.length) {
					steps[i++](step);
				} else {
					f();
				}
			}
			step();
		};
	}

	function wait(delay) {
		return function(f) {
			setTimeout(f, delay);
		};
	}

	function wrap(x) {
		return function(f) {
			f(x);
		};
	}

}