Hannah Recht
Didn't do anything complicated to be clear, but being able to try "format": "%" and have it work is so nice.
Played with Vega on the plane home from #openvisconf. API is so consistent/simple that I could manage editing an example w/o doc access. 
Loading seems to be taking a while.
Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.