[Q] What is ESDFS? topic

I noticed from the list of mounted volumes, that all user data storage volumes appear to be loop mounted using a certain "ESDFS". This ESDFS appears to hide certain android folders such as the .android_secure folder from being accessed. However I have been unable to find any information on this ESDFS on the internet, neither does a search on XDA turn up anything.

So if anyone could enlighten me as to what this ESDFS is exactly, it would be most appreciated.