December 6th, 2003, 13:30
In case you haven't already heard you should read this

The File Allocation Table "affectionately" known as FAT was first introduced in 1976 in MicroSoft Stand Alone BASIC years before MS-DOS and years before software was patentable. All patent numbers listed on the page I linked to above cover Long FileName (LFN) extentions. You can search for the patents here

Currently MicroSoft does not have FOSS in it targets, only embedded device vendors but who knows how long that will last?