Backshift is under a mix of different licenses.
<p>
Most of the code is <a href="GPLv3.txt">GPLv3</a>, with the following exceptions:
<p>
<li>The bufsock and modunits modules are under a <a href="UCI.txt">UCI license</a>
<li>The treap datastructure is under an <a href="Apache2.txt">Apache v2</a> license
<li>The bloom filter code is under an <a href="MIT.txt">MIT</a> license