e2fsprogs (e2fsck) http://e2fsprogs.sourceforge.net/
Design & Implementation http://e2fsprogs.sourceforge.net/ext2intro.html
Journaling (ext3) ftp://ftp.uk.linux.org/pub/linux/sct/fs/jfs/
-Hashed Directories http://kernelnewbies.org/~phillips/htree/
Filesystem Resizing http://ext2resize.sourceforge.net/
-Compression (*) http://www.netspace.net.au/~reiter/e2compr/
+Compression (*) http://e2compr.sourceforge.net/
Implementations for:
Windows 95/98/NT/2000 http://uranus.it.swin.edu.au/~jn/linux/Explore2fs.htm