SpaceNinjaServer is the primary piece of software, and it has many open issues. You can contribute here by doing research regarding open issues, submitting PRs to close those issues, or even opening issues for reproducible problems you encounter.
You can help translate OpenWF software to non-English languages:
We'd appreciate long-term seeding of old versions which are distributed via BitTorrent v1 (all of them except for Steam manifest versions). An RSS feed for them is available at https://about.openwf.io/supplementals/torrents.xml.