Diaspora seems to have fallen of the radar a while back, wondering if anything else is gaining momentum these days either as a direct competitor or a niche alternative
Still very much a work in progress, and far from a full replacement; but it's an open, distributed and secure start:<p><a href="https://github.com/andreas-gone-wild/snackis" rel="nofollow">https://github.com/andreas-gone-wild/snackis</a>