Curseforge: https://www.curseforge.com/minecraft
Modrinth: https://modrinth.com/

Optifine: https://optifine.net/home
Oculus: https://modrinth.com/mod/oculus
Sodium: https://modrinth.com/mod/sodium
Iris: https://modrinth.com/mod/iris

Voice Chat: https://modrinth.com/plugin/simple-voice-chat

Forge: https://files.minecraftforge.net/net/minecraftforge/forge/
Fabric: https://fabricmc.net/

Tweaks: https://vanillatweaks.net/

Spigot: https://www.spigotmc.org/
Bukkit: https://dev.bukkit.org/

Bluemap: https://modrinth.com/plugin/bluemap

Maps: https://www.minecraftmaps.com/