VeraCrypt is a free disk encryption software that is based on TrueCrypt 7.1a. VeraCrypt is a software for establishing and maintaining an on-the-fly-encrypted volume (data storage device). On-the-fly encryption means that data is automatically encrypted right before it is saved and decrypted right after it is loaded, without any user intervention. No data stored on an encrypted volume can be read (decrypted) without using the correct password/keyfile(s) or correct encryption keys. Entire file system is encrypted. VeraCrypt adds enhanced security to the algorithms used for system and partitions encryption making it immune to new developments in brute-force attacks. VeraCrypt also solves many vulnerabilities and security issues found in TrueCrypt.
Thanks to Astron for the update.