Ext2fs

Andreas Dilger - Patch for ext2 online growth
Patch for ext2 online growth
http://ext2resize.sourceforge.net/online.html

Design and Implementation of the Second Extended Filesystem
Paper on the Second Extended Filesystem, ext2.
http://web.mit.edu/tytso/www/linux/ext2intro.html

Ext2 Documentation Project
A project whose aim is to create a complete documentation of the ext2 filesystem.
http://www.nongnu.org/ext2-doc/

EXT2FS
Ext2 file system homepage and utilities.
http://e2fsprogs.sourceforge.net/ext2.html

John's Spec of the Second Extended Filesystem (ext2fs)
File structure compiled from resources published on the Internet, personal experience and Linux source code.
http://uranus.it.swin.edu.au/~jn/explore2fs/es2fs.htm

Linux Ext2 Filesystem for Windows NT driver
Allows read/write access to ext2 partitions from Windows NT. Free.
http://ashedel.chat.ru/ext2fsnt/