Basically: up to 64 channels of digital audio down a single cable. Its a communications protocol (like ADAT light-pipe on stereoids!)
http://en.wikipedia.org/wiki/MADI

stereoids? :hihi:

Practical example: use the MADI output of a Vi6 live console to record to any DAW equiped with a MADI card, using one cable for all 64 channels. (A nice alternative to a D-Show desk plus Pro-Tools)

The biggest benefit being the distance that it can be run; Two kilometers according to that wiki: which explains why it is the format of choice when running live sound.

nice.. Thanks I think I'm getting it. I should read more but want the info here for others too.

I never thought optical would be out performed by cable. I'm guessing this because of the ease of cable (Cat 5/ 6?) rather than the concerns of running a fiber optic cable?

I've never used ADAT, still getting past my old PT Mix system where you simply plug into the back of the 888 24 and away you go.. Although I have moved on to a new system using Firewire , AES or spdif for 2 track, ADAT has never been needed or available to me. There's been no need to look further than what works.

So I think I have it. It sounds like its restricted or specific for controlling the mix of live performances, nothing to do with being an interface in the future? Like a hybrid MIDI but for digital audio? If you want to record, you still use our current interfaces like Apogee Rosetta, FF800, Lavry Blacks, Lynx Aurora 16, Crane Song HEDD... ?

So my next question is, not to panic thinking the these products are being replaced by some MADI? MADI isn't an AD DA interface, correct and never will be?

Its a control interface?

This topic brought to mind where the new and latest recording systems will go in the future...
Obviously Firewire seems to be the most stable and popular....the latest being 32 channels offered in the new A&H GSR24 (coming out soon).
But even FW800 or future FW1000/1600 I've heard about don't seem to be implemented yet?!?
USB3.0 still hasn't surfaced as far as I know with any revolutionary audio protocols....maybe I've missed something.
MADI and AES have been out there for some time now and seems great for a large recording setup with the need for 56-64 channel transmission. And then there's the old standby ADAT (I use 16in/out between the ZEDR16 and FF800) but it's still the FW400 that pumps all 26ch into and out of my computer. So maybe someone has some opinions or comments on the direction the future holds...do we need more channels, more speed, higher definition....whats the next step?

MADI is a type of digital signal just like the ADAT protocol or Firewire protocol. You still need AD/DA converters their just converting to the proprietary digital format of MADI. In a studio situation you would then be able to send 32 channels of MADI out to an analog board for analog sum vice the FF800 or Lavry or whatever.

Seen at RME:
MADI is the Pro Audio Industry standard for multichannel audio. The MADI standard was defined by the AES (Audio Engineering Society). Many factors have influenced the increasing importance of MADI in pro audio production systems. These include an overall growth in the use of digital audio equipment, and the ever increasing demand for greater numbers of audio channels in large productions. Surround sound production has also raised the requirements of multi-Channel applications. MADI is an attractive and convenient interface technology, as it provides the simplest method of transmitting 'sample accurate' audio channels over long distances. The balance between operating distances, installation costs and overall maintenance is exemplary.
Technically, MADI keeps all AES/EBU 24-bit signals in serial, while allowing the sample rate to still vary by +/-12.5%. Time Division Multiplexing is used to fit all audio channels into a single cable. MADI can also be used to transmit high sample rate audio signals. The MADI format is capable of transmitting up to 64 audio channels (at standard sample rates of 44.1 or 48 kHz) on a standard 75 Ohms coaxial cable or an optical fibre cable. The 64-Channel mode was introduced officially in 2001. It allows for a maximum sample rate of 48 kHz + ca. 1%, corresponding to 32 channels at 24-bit / 96 kHz. MADI is unidirectional, providing a 'point-to-point' interface between a source and a destination. The MADI format is fully specified in the AES-10 standard document.
ADI signals can be transmitted by two cable types: Coaxial, max. 100 m (75 Ohms, BNC) and Optical fibre glass, max. 2000 m (62.5/125 µ, standard network technology)
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Also good: it works in star shape and daisy chain config.... and can include Midi...