Recently Opera Software submitted a draft proposal to the World Wide Web Consortium (W3C) that may or may not become accepted as an official W3C Web API working group draft. The proposal calls for the creation of a new Web application programming interface (API) in Web browsers, called File I/O, which in turn will use a new URI scheme called mountpoint. The purpose of the API is to create an abstract method for Web applications to interact with a computer's local file system in a sandbox environment. The API would be compatible with various file systems without the need for any knowledge of which file system type is actually in use (e.g., FAT, FAT32, NTFS, EXT3, ReiserFS).
As I understand it, this is to allow greater capabilities for opera 'widgets'. I confess to never having used any, since I like to keep my web browser for...well, web browsing. I imagine security would have to be pretty tight too. Any Opera widget fans around?