Archive of audios from the Library of Congress of the USA. There you can find early recordings ranging all the way back to the 1850's available for free listen and download. Is quite interesting for sound-related researches.
Have you ever wanted to take the audio output of one piece of software and send it to another? How about taking the output of that same program and send it to two others, then record the result in the first program? Or maybe you’re a programmer who writes real-time audio and music applications and who is looking for a cross-platform API that enables not only device sharing but also inter-application audio routing, and is incredibly easy to learn and use? If so, JACK may be what you’ve been looking for.