Dar is a shell command that makes backup of a directory tree and files. Its features include splitting archives over several files, DVD, CD, ZIP, or floppies, compression, full or differential backups, strong encryption, proper saving and restoration of hard links, extended attributes, file forks, Door inodes, and sparse files, remote backup using pipes and external commands (such as ssh), and rearrangement of the "slices" of an existing archive. It can run commands between slices, before and after saving some defined files or directories (for a proper database backup, for example), and quickly retrieve individual files from differential and full backups. Several external GUIs exist as alternatives to its CLI interface, like kdar, DarGUI, SaraB, etc.
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.
mcrypt is a program for encrypting files or streams. It is intended to be a replacement for the old UNIX crypt. It uses well-known and well-tested algorithms like BLOWFISH, AES, ARCFOUR, CAST-128, and more in several modes of operation. It also has a compatibility mode with the old UNIX crypt program and the des program found in Solaris.
Rsyncrypto allows you to encrypt a file or a directory structure such that they can later be synchronized to another machine using rsync. This means that local changes to the plain text file result in local changes to the cipher text file. rsyncrypto compresses the plain text file prior to encrypting it with gzip using the "rsyncable" patch, which is available from the rsync sources.
The Enhanced File Crypt/eXtended File Stealth System (EFC/XFSS) makes your uploaded files safe on the server so that no one can read them without knowing a few details to decipher the files. It generates different obfuscated names and encrypted files so no one will know what the original format or name was.
Jafe is a small application designed to keep sensitive data organized in an easy-to-use way, with heavy focus on security. It's designed to be accessible on as many systems as possible. It's regularly tested under Windows, Linux, and OS X, JDK 1.4.2 and 1.5, but should work on other systems. It features an easy-to use interface, strong encryption (AES, Twofish, Serpent and Camellia), and plausible deniability. Different data storage backends will be supported: filesystems, embedding into images, saving over the Internet, etc.
Cryptosync is tool that makes compressed and encrypted incremental backups. That way, one can efficiently copy the files to another location with normal rsync. Not only are the file contents encrypted, but also the filename, mode, owner, and group information are stored encrypted.