All platforms: Clonezilla is an open source, Linux-based alternative to commercial disk cloning tools like Symantec Ghost and Acronis True Image. Unfamiliar with the process of disk cloning? In a nutshell, disk cloning makes a copy of a data disk for future restoration. A perfect time to create a clone would be after you'd installed your operating system of choice, your favourite applications, and tweaked the system settings to your liking. The next time you had to wipe your system and do a reinstall you'd save yourself the tedious hours of reinstalling and tweaking. From that point forward you'd have a customised installation on hand.
Clonezilla has support for a multitude of file systems such as ext2, ext3, xfs, FAT, NTFS, and HFS+, ensuring you'll be able to back up any Windows, Linux, or Mac systems you have. Clonezilla images only the used data blocks for increased efficiency on both the initial image and the restoration. Clonezilla comes in two flavors: Live and Server Edition. The Live edition is best suited for home and small business users, the Server Edition requires additional setup for network based distribution of disk images. If you have multiple machines to image the extra setup is worth it—the example deployment on their web site is 40 computers restored in 10 minutes via network distribution. Both flavors of Clonezilla are free downloads. Thanks Michael!