self-hosted: aka "I paid the hosting provider myself"
Plus, I can just throw hardware at it and not increase my monthlies. Hard to get a VPS for what my rent is (under $100/mo), given what I have running (16 Xeon cores across two chips, 72GB DDR3 ECC, 4TB disk, 10Mbps 95th-percentile on a gigabit connection).
Small server part of the pixie.town infrastructure. Registration is approval-based, and will probably only accept people I know elsewhere or with good motivation.