tricks when designing project file formats?

[pir]

Hi!

My program consists of a 3d scene with a lot of objects and settings. I want to write the contents of the whole scene into a project file, like in Maya or Photoshop. So I need to write down all information etc...

I suppose it can be done quite straight forward. But I wonder if someone know about any good siteś about this? Maybe there are some nice techniques that can make this process less painfull...


Painfull stuff I would like to solve:
If I create this project file, and then decide to make some changes to the program like removing information or adding information. This change in information would then make the project file format to change. This would make the old project file formats unreadable... but there must be some nice workaround for this...



thanks for reading
pir