VeraCrypt is a successor of TrueCrypt - it fixed critical bugs of TrueCrypt, provides cross-platform encryption, can encrypt filesystems, uses cryptoresistant algorithms and supports "hidden volumes". And it has a GUI.
Clean and powerful console implementation. Grab a sample script to simplify TC containers management from http://jasonwryan.com/blog/2013/01/10/truecrypt/
This is a console verion only. If you want the GUI you will need to go to the website. Link: http://www.truecrypt.org/downloads
Taking the easy to use TrueCrypt and replacing it with a terminal based alternative sucks. This is a pain in the ass to use.