I think Minecraft server re-implementations are pretty neat and I like to see when a new one comes out. There are also specific purpose server impls like MCHPRS for doing fast redstone compilation for technical minecraft.
Yep block placing and breaking is already supported, but light currently don't so everything is dark :/, We are working on it. Yep, We want to add all cool features like scoreboards, teams and we already have a API which is similar to use to Brigadier for our Commands.
Thanks, I would love to give players on low-end hardware the possibility to host servers. I think i may test Pumpkin on a raspberry PI or something one day
Mojang made large improvements to the lighting engine in 1.20, bringing it in line with the performance mods Phosphor[1] and Starlight[2]. Despite being deprecated now, they might still offer some useful insight into how to approach such a system in a performant way. You'll need to be mindful of the licenses, but it's likely easier than reverse-engineering Minecraft (even with mappings).
I don't see it listed, but is there support for block breaking/placing yet? Presumably this would require light recalculation and a chunk update on the server.
Finally, do you plan to add advanced features like scoreboard, teams, or command block parsing in general? Mojang has at least open-sourced Brigadier for that.
Cool project. Hope to see it mature to the point of making servers easier to run on low-end hardware.