Clonezilla was inspired by these packages and forms an Open source clone system solution. Clonezilla comes with unicasting and multicasting features!! Clonzilla saves and restores only used space in your hard disk. Hence its a lot efficient.
File systems supported by clonezilla
ext2, ext3, ext4, reiserfs, xfs, jfs of GNU/Linux
FAT and NTFS of Windows
HFS+ of Mac OS
For more technical details