Blender 2.5 file format

Hi all,

I am doing some research so I can write a .blend file loader with C++ and I found this article :
which basically describes the format of a blender file, but when I checked I found out that the format of a .blend file from Blender 2.5 is different from that specified by this article!

Do you know of any websites or pieces of information out there which describe the format of a Blender 2.5 file?

Thanks, I need it desperately!!