It is quite often that people who use GNU/Linux together with Windows are confronted with the problem of cross platform file system portability.
Traditionally, many experienced GNU/Linux users have encouraged others facing this problem to dedicate a FAT32 partition to moving files from Windows to Linux, and vice versa. That’s because files stored in FAT32 can be read from and written to by Linux and Windows alike.
While this may be an adequate solution for small drives, it has been increasingly the case in the last few years, that the sizes of files typically used have grown beyond the effectiveness of a FAT32 solution.
This may be attributed to several factors: faster computers, larger data storage devices and faster internet connections. For example, many people download or rip DVD movies, games and music, which even with compression techniques still make rather large files. And video-capture and editing may also easily create file sizes in excess of 4GiB. Whatever the reason, storing and manipulating large files has become very commonplace.
But therein lies the problem: FAT32 is ill equipped for efficiently handling a great multitude of files, or extremely large files for that matter. Particularly when performing a lot of file deletions and writing. It greatly fragments the drive and furthermore it has a 4GiB file size limit, so it would be better to have an alternative.
And that is why I recommend using ext3 instead. It offers full journaling capabilities when working in GNU/Linux, and any system capable of reading and writing ext2 will also be able to have full read/write access as well, although journaling will not be available when the drive is accessed in this manner. Nevertheless, it’s main attraction is that you never need to resort to defragmenting the drive, and it supports file sizes up to 2TiB.
For Windows, there is the excellent ext2 IFS for Windows project. This is what I am using right now, and it works just fine. There are some minor problems (e.g. I’ve had to change the partition type of my USB drive, see also the release notes), but on the whole I’d say it performs quite satisfactory.
And for the Mac, there’s the Mac OS X Ext2 Filesystem project, but to tell the truth I don’t know how well it works, as I do not own a Mac to try it with.