The SimSolutions J-3 Cub for X-Plane 11 was the second aircraft released by SimSolutions, but didn't see many updates, was never updated to X-Plane 12, and eventually pulled from stores at the end of 2024.
Instead of letting the whole thing go to waste, the original source code has been made public under the Apache 2.0 license.
Contributions are welcome, although pull requests may take a while to get to.
Something to note for contributors: The git module under plugins/J3/libs/libacfutils-redist is a mirror of the latest release of the libacfutils redistributable.