KDE-Forum.org

I can't find it either, and it's bugging the heck out of me. In KDE 3.2 or so kate *did* remember some of the window settings. You might want to take this to the kate-devel mailing list (see lists.kde.org for a reasonably full listing of available mailing lists) instead of the forum, though.

Which version do you use? KDE 3.3?
I seem to remember that it's fixed in KDE 3.4, but I don't know exactly.

These settings are made for specific sessions, I guess. So start Kate, choose "new session" and configure the window's layout. Also do not forget to check "Save Window Configuration". Then hide the filesystem browser and and the document list. There is also an option to hide the navigation bar (alt+ctrl+shift+f). Now quit Kate. If you restart Kate now and choose "new session", the filesystem browser and the document list should be hidden.

At least, this worked for me. Opening any other session should result in filesystem browser and document list _not_ being hidden. I did not find a global setting for this, so I guess you have to configure every session this way.

I hope this works for you.