GatKong's GatPack Resource Pack has been around since the days of alpha (when texture packs were a single png file!), updating over the years. GatKong has been getting a lot of requests for legacy versions of his resource pack, and so some of the requested legacy versions can be found here.
The pack tries to be true to the default textures while animating that which shouldn't be static, bringing to life what looks best in 3D, illuminating what shouldn't be dark, connecting what shouldn't be a grid, along with a few other visual and text enhancements.
Minecraft Versions don't match up well with Pack Formats, so here is a guide for relevant versions available here:
Pack Format 46 is most compatible with Minecraft 1.21.4
Emissive (glowing) and unique enchanted book models are the most recent additions. The complete list of pack_format 46 additions are listed here:
v46
-added 3D copper_block models
-added 3D spawner model and texture
-fixed barrel gui texture
-fixed jukebox gui texture
-fixed invisible texture
-updated redstone_torch animated texture
-moved all Optifine emissive related resources into vanilla Minecraft resources
-added improved pale_oak boat models and textures
-added improved pale_oak chest_boat models and textures
-added 3D pale_oak_door models and textures
-added 3D pale_oak_trapdoor models and textures
-added 3D pale_oak fence models and textures
-added 3D book model, texture, and emissive texture
-added 3D enchanted_book unbreaking model, texture, and emissive texture
-added 3D enchanted_book vanishing_curse model, texture, and emissive texture
-added 3D enchanted_book wind_burst model, texture, and emissive texture
-added 3D enchanted_book aqua_affinity model, texture, and emissive texture
-added 3D enchanted_book bane_of_arthropods model, texture, and emissive texture
-added 3D enchanted_book binding_curse model, texture, and emissive texture
-added 3D enchanted_book blast_protection model, texture, and emissive texture
-added 3D enchanted_book breach model, texture, and emissive texture
-added 3D enchanted_book channeling model, texture, and emissive texture
-added 3D enchanted_book density model, texture, and emissive texture
-added 3D enchanted_book depth_strider model, texture, and emissive texture
-added 3D enchanted_book efficiency model, texture, and emissive texture
-added 3D enchanted_book feather_falling model, texture, and emissive texture
-added 3D enchanted_book fire_aspect model, texture, and emissive texture
-added 3D enchanted_book fire_protection model, texture, and emissive texture
-added 3D enchanted_book flame model, texture, and emissive texture
-added 3D enchanted_book fortune model, texture, and emissive texture
-added 3D enchanted_book frost_walker model, texture, and emissive texture
-added 3D enchanted_book impaling model, texture, and emissive texture
-added 3D enchanted_book infinity model, texture, and emissive texture
-added 3D enchanted_book knockback model, texture, and emissive texture
-added 3D enchanted_book looting model, texture, and emissive texture
-added 3D enchanted_book loyalty model, texture, and emissive texture
-added 3D enchanted_book luck_of_the_sea model, texture, and emissive texture
-added 3D enchanted_book lure model, texture, and emissive texture
-added 3D enchanted_book mending model, texture, and emissive texture
-added 3D enchanted_book multishot model, texture, and emissive texture
-added 3D enchanted_book piercing model, texture, and emissive texture
-added 3D enchanted_book power model, texture, and emissive texture
-added 3D enchanted_book protection model, texture, and emissive texture
-added 3D enchanted_book punch model, texture, and emissive texture
-added 3D enchanted_book quickcharge model, texture, and emissive texture
-added 3D enchanted_book respiration model, texture, and emissive texture
-added 3D enchanted_book riptide model, texture, and emissive texture
-added 3D enchanted_book sharpness model, texture, and emissive texture
-added 3D enchanted_book silk_touch model, texture, and emissive texture
-added 3D enchanted_book smite model, texture, and emissive texture
-added 3D enchanted_book soul_speed model, texture, and emissive texture
-added 3D enchanted_book sweeping model, texture, and emissive texture
-added 3D enchanted_book swift_sneak model, texture, and emissive texture
-added 3D enchanted_book thorns model, texture, and emissive texture
-added 3D enchanted_book wind_burst model, texture, and emissive texture
-added 3D enchanted_book unbreaking model, texture, and emissive texture
-added 3D enchanted_book vanishing_curse model, texture, and emissive texture
-added 3D enchanted_book wind_burst model, texture, and emissive texture
-added 3D knowledge_book model and texture
-added 3D writable_book model and texture
-added 3D written_book model and texture