[peerst]

It's all relative. Hard Realtime vs Soft Realtime is not clearly delineated. Because on anything real world there is always a probability distribution for every deadline.

Our observation is that Erlang's "soft-realtime" is already getting much harder once Linux stays out of the way. We have a master thesis worth of research on having multiple sets of schedulers in one Erlang VM that run on different hard real-time priorities plus research on a network of message passing and garbage collecting Erlang processes can be doing Earlies Deadline First scheduling.

However that stayed prototypical because we found relativeness of vanilla Erlang on RTEMS was good enough for all practical customer problems we solved.

For very high performance hard real-time we drop down to C and we are currently working on a little language that can be programmed from the Erlang level that avoids that.