This modpack is based on Fabulously Optimized and has been customized to enhance performance and gameplay in Minecraft 1.21.1 using Fabric. The main focus is on optimizing the game to increase FPS and reduce resource usage. 
Key Features:
Performance Optimization: Mods like Sodium, Lithium, FerriteCore, Entity Culling, and Dynamic FPS work together to make the game run smoother and use less memory and CPU.
Visual Enhancements & Compatibility: Includes shader support with Iris, dynamic lighting, custom textures, and visual improvements (Continuity, CIT Resewn), which are optional and focused on aesthetics.
Configuration and Usability: Includes APIs and tools to ease mod management and settings (Cloth Config API, Mod Menu, YOSBR).
Interface and Chat Improvements: Adds features like extended chat history and better advancement and menu displays.
Note about Texture Packs and Visual Mods: Texture packs and visual mods such as FabricSkyBoxes (Nuit), Animatica, OptiGUI, and others are included but fully optional. Their purpose is to enhance the visual experience without impacting base performance. You can choose to use them or not based on your preference.
This modpack has been tested on a computer with the following specs. I recommend not playing if you experience FPS drops, as I do too, but I still want to play:
CPU: Intel(R) Celeron(R) N4500 @ 1.10GHz
RAM: 4GB (3.8GB usable)
Storage: Generic MMC128
GPU: Intel(R) UHD Graphics
Wifi: Intel(R) Wireless-AC 9560