advanced world generation

I'm trying to develop a frozen neather and I would like to get the originaly way the nether was generated I only know how to make a flat world how would I go about getting the actual nether world generation?

 

http://forums.bukkit.org/threads/chunkgenerators-blockpopulators-faq.22795/ I think this thread addresses it

 

That thread is out of date. Here's a better world generation tutorial however it doesn't go over how to make terrain how minecraft does it. You might be able to get it somewhat close though.

 

Thanks I did research and I learned about block populators that's what I was looking for

wait how would I go about replacing blocks as they're being populated?

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

You could add your own populator to the default world populator for your nether world and then have it loop through all of the blocks in the chunk replacing whatever you find with something else.