[dfox]

ATM failed to see the usage predicted by it's proponents in the 90's. The reason for that is that most of such statements about ATM as the new unified network for everything were mostly marketing bullshit disconnected from technical reality.

ATM is essentially circuit-switched technology lying somewhere between L1 and L2 that allows for efficient QoS for different services sharing same wire at the expense of ludicrous framing overhead and creating networks of such channels with reasonably simple and fast switches. The QoS part is mostly irrelevant today as faster interfaces made the problem significantly easier to solve so is the simple and fast switching. ATM's orientation towards end-to-end circuit-switched channels is what allows fast switches but also requires some external control-plane that builds and tears down the virtual channels, which I think is the major reason why ATM (and OSI in general) didn't catch on, on IP, you just send packet with destination address down the wire, with ATM you have to establish connection first (by using something essentially out-of-band and centralized).

In the end, ATM is widely used today, but mostly as pre-existing way of handling QoS and framing on top of some unrelated but relatively slow L1 technology (ATM is the first higher-level layer of both UMTS and xDSL)