News for hackers. Stuff that matters.
Re:TrueCrypt Security Assessment [pdf] by ewams on Monday April 14, 2014 @12:09PM (#7586992)
TrueCrypt is also opensource: http://www.truecrypt.org/downloads2

The security assessment is for the Windows version of TrueCrypt only. Which also answers your question, TrueCrypt is appealing because it works on *nix, BSD, and Windows. It is also free and open source. The Windows version is easy to use, has a nice GUI and actually works as stated.

Re:TrueCrypt Security Assessment [pdf] by Buge on Monday April 14, 2014 @02:19PM (#7587849)
The license has been criticized as not being truly "Open Source" or "free".

https://en.wikipedia.org/wiki/TrueCrypt#Licensing_and_Open_S...

Wikipedia lists it as "source-available".