Useful

A high-performance rendering engine replacement for Minecraft, which greatly improves frame rates and reduces micro-stutter.

A modern shader pack loader for Minecraft intended to be compatible with existing OptiFine shader packs

Using async path-tracing to hide Block-/Entities that are not visible

Memory usage optimizations

Adds a mod menu to view the list of mods you have installed.

No-compromises game logic optimization mod, useful for both single-player games and multi-player servers.

Speed up immediate mode rendering in Minecraft

All-in-one mod that improves performance, reduces memory usage, and fixes many bugs. Compatible with all your favorite performance mods!

A Minecraft mod that allows for efficient connected textures

A zoom mod with infinite customizability.

Sodium addon providing support for the Fabric Rendering API, based on Indigo

Fixes Minecraft bugs found on the bug tracker

Disable's the Experimental Settings popup, which appears when you create or load world.

Record your Minecraft gameplay, play it back and create stunning cinematic shots

A Level of Detail rendering mod

What the hell is that? A Waila/Hwyla fork.

A tree-style questing mod, allowing pack makers to make and include completable quests for their players

The most customizable free maintenance plugin for your Minecraft server you can find. It runs on Paper, Velocity, Bungee, as well as Sponge.