tangled.org
steveklabnik.com
This is a big issue, I don't expect it any time soon.
Webhooks on various events would be pretty cool, as they'd allow people to expand tangled without you needing to.
One concrete example I'm thinking of is CI. I'd assume that's super far off for y'all, but if I could set up a server that gets notified when someone opens a PR, or when new commits are added... things like that.