Clonezilla is a partition or disk cloning tool similar to Symantec Ghost. It saves and restores only blocks in use on the hard drive if the file system is supported. For unsupported file systems, dd is used instead. It has been used to clone a 5 GB system to 40 clients in about 10 minutes.
Areca is a file backup system that supports data compression (zip / zip64 format) and encryption, incremental backups, FTP/SFTP file transfer, delta storage mode, and many other features. It includes a transaction mechanism, which guarantees the integrity of your backups. Two user interfaces are available: a command-line interface (useful for backup automation) and a graphical user interface (useful for backup administration).
zlib is designed to be a free, general-purpose, legally unencumbered, lossless data-compression library for use on virtually any computer hardware and operating system. The zlib data format is itself portable across platforms. Unlike the LZW compression method used in Unix compress(1), the compression method currently used in zlib essentially never expands the data. (LZW can double or triple the file size in extreme cases.) zlib's memory footprint is also independent of the input data and can be reduced, if necessary, at some cost in compression.
imapsync is a tool for facilitating incremental recursive IMAP transfers from one mailbox to another. It is useful for mailbox migration or backup, and reduces the amount of data transferred by only copying messages that are not present on both servers. Read, unread, and deleted flags are preserved, and the process can be stopped and resumed. The original messages can optionally be deleted after a successful transfer.
PeaZip is a cross-platform file archiver utility that provides a unified portable GUI for many open source technologies like 7-Zip, FreeArc, PAQ, UPX, etc. Creates 7Z, ARC, BZ2, GZ, *PAQ, PEA, QUAD/BALZ, TAR, UPX, WIM, XZ, and ZIP files. It extracts more than 150 archive types: ACE, ARJ, CAB, DMG, ISO, LHA, RAR, UDF, ZIPX, and more. Features of PeaZip include extracting, creating, and converting multiple archives at once, creating self-extracting archives, split/join files, strong encryption with two factor authentication, an encrypted password manager, secure deletion, find duplicate files, calculate hashes, and export job definitions as scripts.
Recovery Is Possible (RIP) is a CD or USB boot/rescue/backup/maintenance system. It has support for many filesystem types (Reiserfs, Btrfs, Ext2/3/4, HFS+, ISO-9660, Squashfs, UDF, XFS, JFS, UFS2, CIFS, MS DOS, NTFS, and VFAT) and contains several utilities for system recovery. It also has IDE/SCSI/SATA, RAID, LVM2, and Ethernet/Wireless network support.
rsync is a replacement for rcp (and scp) that has many more features. It uses the "rsync algorithm" which provides a very fast method for remote files into sync. It does this by sending just the differences in the files across the link, without requiring that both sets of files are present at one of the ends of the link beforehand.
pngcrush is an excellent batch-mode compression utility for PNG images. Depending on the application that created the original PNGs, it can improve the file size anywhere from a few percent to 40% or more (completely losslessly). The utility also allows specified PNG chunks (e.g. text comments) to be inserted or deleted, and it can fix incorrect gamma info written by Photoshop 5.0 as well as the erroneous iCCP chunk written by Photoshop 5.5.
HTTrack is an easy-to-use offline browser utility. It allows you to download a Web site from the Internet to a local directory, building recursively all directories, getting HTML, images, and other files from the server to your computer. HTTrack arranges the original site's relative link-structure. Simply open a page of the mirrored Web site in your browser, and you can browse the site from link to link, as if you were viewing it online. HTTrack can also update an existing mirrored site, and resume interrupted downloads. WebHTTrack is a Web-based GUI for HTTrack.