I have tried a few times in past months without success to compile the rAthena Ragnarok Online server emulator on my Raspberry Pi 3. Well, just for grins, I pulled the latest source the other day and took another crack at it – BINGO! Looks like the latest source will compile on armhf arch. Since the previous KalistoRO server was well in its infancy, I just elected to go with a clean database rather than mess with pulling over the existing data.
So far, the server runs quite well. While I have not had the time to really hammer it, the bit of stress-testing I have done has been absorbed by the Raspberry Pi with it not even breaking a sweat.
The KalistoRO is still in beta (it pretty much always has been), but up and running. So, go grab the client and go to town!