Quilt reached out to me and suggested I chime in suggesting that people interested in versioning data also check out Dolt (https://github.com/liquidata-inc/dolt) and DoltHub (https://www.dolthub.com).
We've taken the Git and GitHub for data analogy a lot more literally than Quilt has :-) We are a SQL database with native Git semantics. Instead of versioning files like Git, we version table rows. This allows for diff and conflict detection down to the cell level. We are built on top of another open source project called Noms (https://github.com/attic-labs/noms).
We think there is a ton of room in this space for a bunch of tools: Quilt, Noms, QRI (https://qri.io/), Pachyderm (https://www.pachyderm.io/), and even Git. We're excited to see so many bright minds trying to solve this problem.
We're going to be populating DoltHub with a bunch of datasets we harvest from the open data community to show off the capabilities of Dolt. The coolest one so far is the Google open images dataset: https://www.dolthub.com/repositories/Liquidata/open-images.