I've been creating a new open source trophy/achievement system called Gamerzilla. There is a thread about it in the projects forum. SuperTuxKart already has an achievement system. How would the developer feel about adding in Gamerzilla support? Gamerzilla support would allow you to display achievements in game launchers like GameHub. It would all you achievements to be uploaded to Hubzilla site running the Gamerzilla plugin.
The project is my attempt to stop the spread of closed source achievement systems like Steam or GOG. I need game support to build progress on that goal. If someone wants to add support that would be great. I would offer any help I could. If no one is interested but the maintainers are interested in the idea, I could try to find the time to add support.