Design a decentralized protocol that can handle voting/karma, while also incentivising developers of clients. The problem is that this is not easy.
I agree that this is Reddit's main feature. However it isn't necessarily good. It is basically an amplification of "interest" whether that is good or bad. Assuming that votes represent general quality is a dangerous mistake.
> continually polished user interface
Ok, this must be a joke.
> Design a decentralized protocol that can handle voting/karma, while also incentivizing developers of clients.
In order to do this in a decentralized manor you need to choose who's votes you trust. This is a very interesting problem and solving it may be helpful even in the context of a centralized network.
Maybe but if we let voting/karma/moderation be "perspectives" of the content rather than lossy filters, then it won't matter much.
> you need to choose who's votes you trust.
If users can freely choose their "root" in a trust tree, then it might be interesting. Each upvote confers trust and "karma".
AFAICT there's no consensus model for federated or distributed services that can go fast. So you'd better get your design right the first time around to minimize tweaks and changes. That requires domain expertise, and FOSS is famously bad at paying what it costs for that.