TrueCrypt

[TrueCrypt is not exactly "Open Source", but the source is available. See the reviews to get more information.] TrueCrypt is a disk encryption software for...

• Discontinued Currently unmaintained. Last version, TrueCrypt 7.1a, is still available for download and development has continued via the forks https://alternativeto.net/software/veracrypt/ and https://alternativeto.net/software/ciphershed/. "The development of TrueCrypt was ended in 5/2014 after Microsoft terminated support of Windows XP. Windows 8/7/Vista and later offer integrated support for encrypted disks and virtual disk images."

Free Open Source Mac Windows Linux

GnuPG

GnuPG allows to encrypt and sign your data and communication, features a versatile key management system as well as access modules for all kinds of public key...

Free Open Source Mac Linux PortableApps.com Xfce OpenPGP

AES Crypt

AES Crypt is an advanced file encryption utility that integrates with the Windows shell or runs from the Linux command prompt to provide a simple, yet powerful, tool for...

Free Open Source Mac Windows Linux Android iPhone ... Android Tablet iPad

CipherShed

CipherShed is a program that can be used to create encrypted files or encrypt entire drives (including USB flash drives and external HDDs).

• Discontinued No releases since Sep 6, 2017. See https://www.ciphershed.org/news/

Free Open Source Mac Windows Linux

Windows BitLocker

BitLocker Drive Encryption is a data protection feature that integrates with the operating system and addresses the threats of data theft or exposure from lost, stolen...

Commercial Windows

Kleopatra

It supports managing X.509 and OpenPGP certificates in the GpgSM keybox and retrieving certificates from LDAP servers.

Free Open Source Windows Linux GnuPG

EncFS

EncFS provides an encrypted filesystem in user-space. It runs without any special permissions and uses the FUSE library and Linux kernel module to provide the filesystem...

• Warning The author has agreed that EncFS in its current form is dangerous (to security) for several reasons. Wikipedia has a brief summary: https://en.wikipedia.org/wiki/EncFS#General_Security_Concerns The actual audit, which the author participated in, is here: https://defuse.ca/audits/encfs.htm

Free Open Source Mac Linux BSD

Encrypto

Encrypto lets you encrypt files before sending them to friends or coworkers. Just drop a file into Encrypto, set a password, and then send it however you normally would...

Free Mac Windows

GPG Suite

GPG for Mail is an open source plugin for Apple Mail. Encrypt, decrypt, sign and verify mails using OpenPGP with a few simple...

Commercial $ $ $ Open Source Mac GnuPG

DiskCryptor

DiskCryptor is the only truly free solution, provided under GNU General Public License (GPLv3), which offers encryption of all disk partitions, including the system...

• Discontinued The last update was released 09.07.2014.

Free Open Source Windows

encfs4win

This is an experimental project of porting encfs to the Windows world. Use First time install required Dokan library; Extract executable (or compile by your...

Free Open Source Windows

LibreCrypt

LibreCrypt (formerly DoxBox) is an open-source disk encryption for Windows and the successor of FreeOTFE Change of name to 'LibreCrypt' in version 6.2 ...

• Discontinued Last release Nov 24, 2015 https://github.com/t-d-k/LibreCrypt/releases

Free Open Source Windows

Unicode Crypter

Unicode Crypter is a portable tool that encrypts and decrypts any Unicode character from 1 to 1114111!

Free Windows

FileVault

FileVault is a method of using encryption with volumes on Mac computers. Encryption and decryption are performed on the fly. FileVault 2 uses full disk, XTS-AES 128...

Free Mac

FreeOTFE

FreeOTFE is a free, open source, "on-the-fly" (OTFE) disk encryption program for PCs running MS Windows and Windows Mobile PDAs (FreeOTFE4PDA). It creates...

• Discontinued Discontinued per Wikipedia page (https://en.wikipedia.org/wiki/FreeOTFE)

Free Open Source Windows Windows Mobile