I was unsatisfied with Exalm's ports of the old Minecraft noise generators in NBXlite (one of the mods included in this modpack), so I ported my own noise generators while adding new ones alongside their math helpers. I wanted NBXlite to live up to the standards of today's Minecraft mods that reimplement terrain generators from Minecraft's past; like NostalgiaGen, Indev World Gen, InfGen, and Modern Beta. This is supposed to be a quality-of-life improvement for NBXlite and I hope you'll enjoy it, because I made this fork using Retro MCP-Java, Recaf, and Notepad++ all by myself. I want you to keep something in mind; I am not a programmer; I am a visual artist who likes to draw cartoon animals in front of abstract backgrounds for fun. So please, do not label me as a Java developer because I don't have the sufficient knowledge of Java to earn that title.
DISCLAMER: This modpack is specifically designed to be used in MultiMC.
1 - Create a new MultiMC instance (the version of Minecraft must be Release 1.6.4 respectively).
2 - Click on "Edit Instance".
3 - Click on "Add to Minecraft.jar" and select the "OldDays Revisited v1.8" jar that is contained in this zip folder.
4 - Click on "Open .minecraft" and drag-and-drop the "WorldEdit" jar into the ".minecraft" folder that is in your MultiMC instance.
That's all you have to do! You should now be able to lunch the game in MultiMC!
Here's another thing! When you're playing with this modpack, press the "H" key on your keyboard to bring up the OldDays menu. You can feel free to mess around with the settings. You can press the same key to exit the menu.