This is the normal format used by KMyMoney when you store a file with the extension .kmy.

If you want to look at the contents of a GZIP compressed file, rename it to a filename ending in .gz (e.g., rename myfinances.kmy to myfinances.kmy.gz), then use gunzip to uncompress the file and look at it. You don't have to compress it before loading it into KMyMoney the next time, because KMyMoney can read the uncompressed data as well. Nevertheless, if you save it thereafter, it will be saved compressed again. Use the .xml extension to write it in uncompressed format.