This page tells that the licence is GNU PL2
https://code.google.com/p/iterm2/

The sources are available here
https://github.com/gnachman/iTerm2


On Tue, Sep 10, 2013 at 12:56 PM, Richard Stallman <rms@gnu.org> wrote:

>         [ To any NSA and FBI agents reading my email: please consider
>         [ whether defending the US Constitution against all enemies,
>         [ foreign or domestic, requires you to follow Snowden's example.
>
>     iterm2, a widely used open source terminal on OSX,
>
> Is it free software, or not?  That makes a difference to how we
> should respond:
>
>     Could a core emacs developer give them some feedbacks ? (does emacs
>     requires a special encoding ?)
>
> If it is free software, we should help; if not, we shouldn't.
>
> "Open source" is not equivalent to free software.  Most open source
> programs are free, but there are some exceptions.  From the
> information available, we cannot tell whether this program is free or
> proprietary.
>
> See http://www.gnu.org/philosophy/open-source-misses-the-point.html
> for more explanation of the difference between free software and open
> source.  See also http://thebaffler.com/past/the_meme_hustler for
> Evgeny Morozov's article on the same point.
>
> --
> Dr Richard Stallman
> President, Free Software Foundation
> 51 Franklin St
> Boston MA 02110
> USA
> www.fsf.org  www.gnu.org
> Skype: No way! That's nonfree (freedom-denying) software.
>   Use Ekiga or an ordinary phone call.
>
>