[IanCal]

There's definitely a lot that's interesting to me in it. It's a tricky programming environment, which I find personally fun, but it's an entirely public global database with stored procedures and custom row level security. Every stored procedure can call others written by anyone and there's a strong direct push towards open interfaces and interoperability.

Unfortunately one of the easiest things to make with it is a new "currency" because it fits so well with the security model.