exFAT file system

Does anyne know the earliest version of OSX that could read/write to exFAT? My 10.6.8 can and could before I updated it; a friend's 10.5.something can't, and her's is fully updated.

I find exFAT particularly useful as I use both Win7 and OSX, and exFAT works with large files on both. FAT32 has a 4gb size limit. exFAT works in my experience with Win7 and Vista, but not with XP.

it's in Disk Utility. I've never used it though, don't have a lot of need for either FAT.. or files over 4GB on an external drive.

I didn't use Disk Utility on Snow Leopard - it just worked "out of the box". But my friends' 10.5 (don't know the name) doesn't.

What that means, is that you can format in exFat. One would surmise support for the file system from that.