Erebus is a free photorealistic renderer, written in C++11.
Copyright (C) 2014 John Tsiombikas <firstname.lastname@example.org>
This program is released as free software, under the terms of the GNU General Public License v3, or at your option, any later version published by the Free Software Foundation.
Canonical repo (hg):
GitHub (mirror): https://github.com/jtsiomb/erebus
Take a look at these development progress shots to see what's cooking.
This program is in a very early stage of development. Don't bother trying it yet.