The 3D rendering software behind films such as Toy Story, Monsters Inc and Harry Potter is to be given away free for non-commercial use.
RenderMan, which is developed by Pixar, has faced increased competition from rival animation rendering programmes such as VRay and Arnold.
Although Pixar, which is owned by Disney, produces its own films, it licenses RenderMan to rival studios.
The company has also cut the price of its software for commercial use.
In a statement, the firm said it would release a free version of RenderMan "without any functional limitations, watermarking, or time restrictions".
"Non-commercial RenderMan will be freely available for students, institutions, researchers, developers, and for personal use," it added.
Ian Dean, editor of computer graphics magazine 3D World, told the BBC the move "could be seen as a reaction to the rise of alternatives such as Arnold," but that Disney/Pixar are also looking to "build a community".
He added that RenderMan, which has been around for more than 25 years, was "very important at the higher end of the entertainment, animation and visual effects industries".
The new version of RenderMan was unveiled in London, which has become a global hub for the visual effects (VFX) industry.
Pixar's business director Chris Ford said his company chose to make the "most important announcement concerning RenderMan in over a decade" in London because of the importance of its VFX community.
Lee Danskin, the technical director of Escape Technology, which sells RenderMan to VFX houses in the UK, welcomed the move, saying the software would be more widely adopted as a result.
"In the last 18 months, a lot of new players have entered the marketplace," he told the BBC.
"They got there quicker than Pixar, but this is Pixar's answer - and it's quite an answer."
But, Mr Danskin explained, RenderMan is "not something you can just pick up and start using" as familiarity with animation software is a pre-requisite.
MPC Film - the company that did the visual effects for Game of Thrones, Godzilla and Life of Pi - said it welcomed the free RenderMan release, as it would acquaint up-and-coming artists with the software.
"It's great news that anyone with an interest in computer graphics will be able to have free access to a state of the art renderer from Pixar, the very same software that the world's leading computer graphics artists use to render the images seen in the vast majority of feature animation on live action visual effects films," Nick Cannon, director of technology and operations at MPC Film told the BBC.
The new version of the software is due to be released ahead of the Special Interest Group on Graphics and Interactive Techniques (Siggraph) conference in August.