File Compressors
Winzip
With more than a billion downloads, WinZip is the world’s leading provider of zip utilities and one of the most popular and trusted applications in the history of the Web. WinZip Computing, a Corel company, draws on its core strength as the #1 zip software provider to deliver the power of compression and encryption to where it’s needed most – email, mobile, social media and online. WinZip's offerings include apps for Windows, Mac, iOS and Android, the ZipSend and ZipShare online services, and WinZip System Utilities Suite.
Winrar
WinRAR is a shareware file archiver and data compression utility developed by Eugene Roshal and distributed by Ron Dwight, first released in autumn of 1993. It is one of the few applications that is able to create RAR archives natively, because the encoding method is held to be proprietary.
7-zip
7-Zip is an open source file archiver. 7-Zip operates with the 7z archive format, but can read and write several other archive formats. The program can be used from a command line interface, graphical user interface, or with a window-based shell integration. 7-Zip began in 1999[1] and is actively developed by Igor Pavlov. The cross-platform version of the command line utility, p7zip, is also available. 7-Zip is open source software. Most of the source code is under the GNU LGPL license. The unRAR code is under a mixed license: GNU LGPL + unRAR restrictions. It was the winner of the SourceForge.net 2007 community choice awards for "Technical Design" and for "Best Project".
HJ Split
This program is available on Windows, Linux and a variety of other platforms. Why should one want to split and recombine files? For instance, think of a file of 50 Mb, and try to send it to a friend, post it in a newsgroup or upload it to a Website or FTP server. It is usually easier to send/receive, upload/download smaller parts than handle the entire file in one go. HJSplit can also be useful for backups. A file of e.g. 10 gigabytes in size can be split into smaller parts which then can be burned to CD's, DVDs, copied to USB sticks or uploaded to an online backup service. HJSplit for Windows and Linux support file sizes of over 100 Gigabytes, MD5 checksums, file-compare, "run without install" and both editions are fully portable.
TrueCrypt
TrueCrypt is a freeware software application used for on-the-fly encryption (OTFE). It can create a virtual encrypted disk within a file or encrypt a partition or (under Microsoft Windows except Windows 2000) the entire storage device (pre-boot authentication).