What It Does
Iris loads shader packs in Minecraft. It targets compatibility with shader packs already built for OptiFine, so you can drop in a pack you already have instead of hunting for an Iris-only version. It's listed on Modrinth under Building and Decoration and Performance, which gives a sense of what it's aimed at, visual overhaul plus running well.
Why It Exists
The project grew out of a specific gap. OptiFine's license makes it hard to tinker with or extend, and OptiFine doesn't play nice with Sodium, a popular rendering optimization mod. The older ShadersMod stopped getting updates after Minecraft 1.12 and never picked up support for newer packs. Real talk, iris was built to fill that space, an open shader loader that stays compatible with old OptiFine packs while working alongside optimization mods rather than against them.
What It's Aiming For
The project states a handful of goals it's working toward, not all of them fully realized yet. Performance when paired with mods like Sodium, correctness in the shader pipeline, staying usable inside modded setups, and keeping old shader packs running without edits are all listed as targets. The project is also open about where things stand, some minor OptiFine features are still missing, and general performance work is ongoing.
Compatibility
Iris runs on Fabric and Neoforge. Supported Minecraft versions are 26.2, 26.1.2, 26.1.1, and 26.1. It needs to be installed on the client, server side isn't supported, so there's no server jar variant of this. Almost all existing shader packs work with it, though the project keeps a public list of shader packs that don't work yet, plus a separate list of quirks that can't be fixed given how Minecraft's rendering works.
Who It's For
This is for anyone who wants to run existing shader packs, the same ones built for OptiFine, on a newer Fabric or Neoforge setup, and who also wants to run alongside performance mods rather than choose between visuals and framerate. If you're maintaining a modpack that needs both graphical mods and rendering optimizations in the same instance, this is built with that combination in mind.
Support and Contributing
The project runs a Discord server for troubleshooting and update announcements, and publishes developer documentation for anyone who wants to build the mod from source or contribute code. Iris is coded by coderbot and licensed under the GNU Lesser General Public License v3.0 only.
