I read the bit on OSGi. It seems to support interfaces, runtime loading and unloading of modules, and a way to discover modules. Java 1.0 did all that stuff natively, though JPMS adds some more capabilities, since I guess people don’t like package private, etc.

C++ also supports these things. (C does too, but you need non-standard dynamic linker constructor/destructor extensions that are available on all platforms).

I can’t think of any widely used language without support of such things.