CAVEAT: This is an out-of-date repository, and may actually be deleted soon. Interested parties are encouraged to check out the specification at http://w3c.github.io/filesystem-api/Overview.html
And the "live" repository is at: https://github.com/w3c/filesystem-api
This is the FIleSystem API as discussed on public-script-coord@w3.org and on public-webapps@w3.org. This document will eventually be migrated over to https://github.com/w3c
Till the migration to the W3C GitHub Repo, to temporarily preview the emerging specification, you should look at:
http://htmlpreview.github.io/?https://raw.github.com/arunranga/filesystem-api/master/Overview.html