I am currently in process to designing a new patchingformat and am looking for suggestions from tool developers.
My plan is to release code to read and write this patchingformat (first for vb) as soon as its completed. Incuded will be some examples on how to use it and a class to read and write mul data.
The format is defined on this post:
http://mrfixit.servehttp.com/uogbb/viewtopic.php?t=100
The way the files should be patched is created by any program that makes the patches, so the patcherprograms should work even if support for new datafiles are added.
The patchformat also let you walk around the limitations of some of the muls. Example: Tiledata.mul and hues.mul can be manipulated by one item at a time, instead of going by the block (that has 8 items).