I built this utility with the help of two colleagues[0][1] after working on accessibility at Khan Academy for a few weeks, and seeing first-hand the process of evangelizing accessibility on a dev team. Our automated tests were far from approachable (and became more annoying than helpful), so we built tota11y to make the manual testing experience more interactive and educational (we like teaching things).
I touch on this in our engineering blog [2]
Anyway, super thrilled to see tota11y near the top of HN this morning, and happy to answer any questions you may have.
[0]: https://twitter.com/himichelletodd