Free and simple TrueCrypt Implementation based on dm-crypt

 tcplay is a free (BSD-licensed), pretty much fully featured (including
 multiple keyfiles, cipher cascades, etc) and stable TrueCrypt implementation.
 .
 This implementation supports mapping (opening) both system and normal
 TrueCrypt volumes, as well as opening hidden volumes and opening an outer
 volume while protecting a hidden volume. There is also support to create
 volumes, including hidden volumes, etc.
 .
 Since tcplay uses dm-crypt it makes full use of any available hardware
 encryption/decryption support once the volume has been mapped.