Seems like an interesting effort. A developer is building an alternative Java-based backend to Lemmy’s Rust-based one, with the goal of building in a handful of different features. The dev is looking at using this compatibility to migrate their instance over to the new platform, while allowing the community to use their apps of choice.
I’m a Java developer and I would much rather pick up Rust to join an active project than try to rebuild something that already works using a less-marketable language.