MinecraftForge/MinecraftForge — pull request #64 by richardg867 (2012-05-29 19:23:43+00:00)
Title: Custom world (level.dat) and chunk data

Allows writing and reading custom data in level.dat (WorldInfo) or in individual chunks (Chunk).

A possible usecase for chunk data is ThaumCraft, but I'm yet to contact Azanor.

Most likely not to apply automatically, since a MCP name in AnvilChunkLoader has changed, and this was done before client FML came out.