[stevan]

In the 70s Ericsson programmed their telephone switches in a proprietary language called PLEX. It had hot code swapping, so when Joe Armstrong started working on Erlang to replace PLEX in the 80s this was a requirement. Dropping a few thousands of calls just to do an update simply wasn't an option.

[capableweb]

On the other hand, even the first versions of lisps (as far as I can gather at least) had `eval`, meaning a running program could accept external output and update itself. And this was in the 60s.

The question remains :)

[lispm]

Lisp would also be able to compile code to assembler, run an assembler and load the generated code into the runtime.

I would think (without knowing too much about Erlang's mechanisms) that the mechanisms of Erlang are quite different from what a Lisp runtime typically does. The Lisp runtime is just one process. Erlang is concerned with multiple processes, which are strongly isolated.