NINJAM is a program to allow people to make real music together via the Internet. Every participant can hear every other participant. Each user can also tweak their personal mix to his or her liking. It uses compressed audio which allows it to work with any instrument or combination of instruments. You can sing, play a real piano, play a real saxophone, play a real guitar with whatever effects and guitar amplifier you want, anything. If your computer can record it, then you can jam with it.

The Advanced version of the NINJAM Client and the Servers can be downloaded here.