I need to capture/record audio of a single application. Other applications, with sounds, may run simultaneously, but I only want the output of a single one. The microphone needs to work while doing this as well (though it's not the microphones output I want). The captured audio should preferably be written to wave file continuously.
I'm running Win 7 x64. I've noticed that the application "Livestream Producer" seems to be able to grab the output of games, so I guess it should be possible somehow.
For Mac OS X, there seems to be programs which accomplish this, like "WireTap", "SoundFlower" and "Audio Hijack".