For those who can't find it:
Quote: "As a further commitment to the advancement of open standards and practices, Pixar is announcing that,in conjunction with the upcoming release, free non-commercial licenses of RenderMan will be made available without any functional limitations, watermarking, or time restrictions. Non-commercial RenderMan will be freely available for students, institutions, researchers, developers, and for personal use. Those interested in exploring RenderMan’s new capabilities are invited to register in advance on the RenderMan website to access a free license for download upon release."