Capturing output sound

Hi everybody. Does anybody know how to capture sound from all programs currently running? I mean output sound. There are recorders that do that. I wonder how?

What you need is called an 'audio loopback'. Try searching for that on Google, you should be able to find a program you can download that does this.

It works by installing its own device driver, which you can select as the default audio output device - except it doesn't correspond to any real device, it just plays the audio back in through the audio input.

Thanks, Nathan. That was really helpful. I'm currently communicating with author of Virtual Audio Loop driver)

Hey, I'm interested in that as well.
How it works i do know, i mean the driver issue.

But i'm not into developing the driver thing to much, but i'd like to do similar stuff, I want to be able to manipulate the outgoing audio stream in my oen programm.

Are there driver out there, which i can use? Does not need to be open source, but with a possibilite to communicate or use the dll with c/c++.
I just want to get access to this audiostream and don't wanna write the driver myself.

Any hints would be nice.

Thank you
leechlife

Ps: You talk about "virtual Audio loop driver". I can't find that on google(maybe I'm just blind). Can you give a link, please?