Cross-platform usable filesystem with large file support
Solution 1:
Look at "OS support" on the Comparison of filesystems page on Wikipedia. This lists OS support by file system.
As you can see, there is no file system that is covers all OS platforms, the closest being FAT16. FAT32 is a close 2nd, requiring 3rd party driver support for z/OS.
Since you require read/write support and large files and file systems, the best option would be NTFS. Obviously, Windows OSs support NTFS. Modern Linux kernels (2.2+) can read and write NTFS natively. OS X supports reading NTFS natively and writing with NTFS-3G.