I appreciate the fun one can have at building programs and tools that do something thought to be impossible. Running Java code on a Commodore C64 is such a project.
Back to the Future Java (b2fJ) aims at bringing the power of Java to 8-bit home computers of the ’80s. This project provides a toolchain to cross-compile Java programs under Windows.
You’ll find everything about “b2fJ – Back to Future Java” on Github.