I know that module-info.java is recognized by jdk9+
I wonder however whether module-info.java can still be used in combination with target level 8.
E.g. I want my library to be used in java9+ projects, which will recognize it as a module exporting specific packages, but also be used in java8 projects as a plain jar file.
The Multi-Release JAR files are meant for the exact same purpose itself.
For an example of this based on Maven, take a look at this - maven-jep238.