Unity plugin Shader Forge has contributed to the stylish looks of games such as The Chinese Room’s Dear Esther and Monomi Park’s Slime Rancher, and until today, it has cost $90. Developer Freya Holmér announced that it is now a free, open-source tool, and released the code on GitHub. Shader Forge is available in the Unity Asset Store.

Holmér has decided to pursue other projects, and she decided to make the tool free and open-source because she no longer has the bandwidth to support it anymore. In addition to creating the plugin, Holmér cofounded the indie studio Neat Corporation, which is making the VR game Budget Cuts.

Developers use shaders to create a range of visual effects in their games, both 3D and 2D. Surface shaders affect how game objects interact with light, while other types of shaders, like vertex and fragment, can affect something’s color or rasterization, which helps with smooth animation. Some developers create their own shaders — for instance, Mike Blackney for his upcoming “Grand Theft Cthulhu” game Dead Static Drive — but many others use tools so they don’t have to code from the ground up.

Holmér’s Shader Forge was one of the earliest of these tools, and it originally launched in 2013. Unity now has its own shader tool, but at one point, she was in talks with the company about the possibility of an acquisition.

“Unity did in fact start that conversation with me years ago. But we ended up not reaching a deal, not because they gave me a bad one, but because our goals simply weren’t aligned,” said Holmér in a series of Tweets. “The deal was, in short, that Unity would acquire Shader Forge and hire me to work on an officially integrated shader editor. Which was a great deal, but a difficult decision for me to make at the time, because I ultimately want to create games, not tools.”

As Shader Forge joins the ranks of free development tools like Unity itself and fellow game engine Unreal, more developers will have the option to experiment with their processes and innovate further on the games they create.