TrueCrypt isn't open source software, in spite of the author incorrectly claiming it is. More detail is here, which the author could have learned in 2 minutes of Googling: http://en.wikipedia.org/wiki/T... ... for your amusement, I have quoted it below:
TrueCrypt was released under the "TrueCrypt License" which is unique to the TrueCrypt software. It is not part of the pantheon of widely used open source licenses and is not a free software license according to the Free Software Foundation (FSF) license list, as it contains distribution and copyright-liability restrictions. As of version 7.1a (the last full version of the software, released Feb 2012), the TrueCrypt License was Version 3.0.
Discussion of the licensing terms on the Open Source Initiative (OSI)'s license-discuss mailing list in October 2013 suggests that the TrueCrypt License has made progress towards compliance with the Open Source Definition but would not yet pass if proposed for certification as Open Source software.
According to current OSI president Simon Phipps:
...it is not at all appropriate for [TrueCrypt] to describe itself as "open source." This use of the term "open source" to describe something under a license that's not only unapproved by OSI but known to be subject to issues is unacceptable.
As a result of its questionable status with regard to copyright restrictions and other potential legal issues, the TrueCrypt License is not considered "free" by several major Linux distributions and is therefore not included in Debian, Ubuntu, Fedora, openSUSE, or Gentoo.
The wording of the license raises doubts whether those who use it have the right to modify it and use it within other projects. Cryptographer Matthew Green noted that "There are a lot of things [the developers] could have done to make it easier for people to take over this code, including fixing the licensing situation", and speculates that since they didn't do those things (including making the license more friendly), their intent was to prevent anyone from building on their code in the future.
End of life and license version 3.1
The 28 May 2014 announcement of discontinuation of TrueCrypt also came with a new version 7.2 of the software. Among the many changes to the source code from the previous release were changes to the TrueCrypt License — including removal of specific language that required attribution of TrueCrypt as well as a link to the official website to be included on any derivative products — forming a license version 3.1.
On 16 June 2014, the only alleged TrueCrypt developer still answering emails, replied to an email by Matthew Green about the licensing situation. He is not willing to change the license to an open source one, believes that Truecrypt should not be forked, and that if someone wants to create a new version they should start from scratch.