VeraCrypt - VeraCrypt is a free open source disk encryption software for Windows, Mac OSX and Linux.
TrueCrypt - TrueCrypt is a leading cross-platform that provides encryption tools that allow you to migrate any encrypted data to virtual disks images on your systems.
BoxCryptor - Boxcryptor encrypts your sensitive files before uploading them to cloud storage services like Dropbox, Google Drive, Microsoft OneDrive, Box, and many others.
Cryptomator - When it comes to saving your files on a cloud server, it is important to ensure the security of those files. Keeping your delicate files out of the wrong hands can save you a lot of time and hassle. Read more about Cryptomator.
LUKS - LUKS is the standard for Linux hard disk encryption.
Axcrypt - AxCrypt - Password Protect Files With Strong Encryption. AxCrypt is the leading open source file encryption software for Windows.