[sheenobu]

OSGi (Open Services Gateway initiative) [1] provides this for the JVM by modularizing the ClassLoader [2]. If a module is upgraded but classes from the previous version are still referenced by other modules, both modules will run.

An OSGi "service" is not an actor but, like OTP with servers+supervisors, is the logical unit with which you build your systems. "bundles" (Java JARs with additional metadata) then act as the equivalent "application" that contain the services.

Outside of it being Java, I have strong opinions (positive and negative) that I've decided not to include.

[1] https://en.wikipedia.org/wiki/OSGi [2] https://en.wikipedia.org/wiki/Java_Classloader