Real-time internal audio routing between software

Just wondered if anyone has heard of something like this. For example, sometimes I would like to route the output of Sonar 8 straight into MaxMSP and then output the sound. Or vice-versa. It would need a neat program to - perhaps - route the output of Sonar (or any other program that outputs audio and is non-VST) back into your soundcard's audio input. As long as Sonar isn't echoing any of the inputs, you could just open up MaxMSP, adc~ and you're off. I've had several times when I thought to myself, if only...

Ivan Reshetilovhttp://www.ivanreshetilov.co.uk