It would be great to see a Fediverse GitHub alternative. Obviously we have plenty of self-hosted software forges around, but I'm not aware of any decentralized network solution. Allow people to host repositories on an instance, but be able to search, discuss and contribute to repositories across the entire network. That way you'd get the benefits of a large programmer community without needing to centralize to a single company or organization. Maybe this already exists and I'm unaware.