7-zip Can extract from a wide range of archive files as well as several installers. Can build zip, gzip, tar, files plus “7z” files that can be AES encrypted. Unlike some other compression tools, doesn’t whine about registering or handing over cash. The author does accept donations, however.
 Clonezilla Copy a whole disk or partition to an archive or a similar size disk. Makes it easy to build a duplicate workstation or rebuild one after a crash. (bootable CD) This is one of the more mature (and free) disk-imaging tools. The Server Edition (also free) can even multicast disk images to workstations bootable with PXE/Wake-on-LAN.
 DirSync Pro Supports both two-way syncing and one-way backups. Only copies new or updated files in the specified direction. Can also keep backup copies of any files deleted during a sync. Although it does require Java Runtime, it does not need to be installed - just run the executable. Since it is file-system agnostic, unfortunately VSS is not supported.
 SpiderOak Unlike many competitors, their cloud storage security is a "no-knowledge" scheme that prevents them from seeing your encryption keys.  Their backup/sync software and a team collaboration tool called "Semaphor" both use this scheme. Since they no longer have a "2GB free" plan I am looking at some newer alternatives like IDrive.  However, a "basic" version of Semaphor (with limited retention) is free.
 cryptsync CryptSync CryptSync is a simple encryption tool that synchronizes the content of any clear-text folder with an equivalent encrypted folder. This lets you safely use DropBox, OneDrive, GoogleDrive, etc. with truly private encryption.  All files in the encrypted folders are saved as AES encrypted 7zip archives. While the original product I used for secure cloud storage (Viivo) has been discontinued, I found that this is actually a better and more reliable tool.  Apart from being free and open-source, CryptSync also allows file and folder name encryption.  Even more importantly, unlike Viivo, it won't crash the windows shutdown process.