Novinyl is a lightweight desktop database for KDE. It only supports flat data, no SQL or even simple linked data.
Its original purpose was to store music collections, but as you can see in the screenshots it's useful for other kind of data as well.

Novinyl 0.3 (28.11.2002):
novinyl-0.3.tar.gz (Source tarball)
Novinyl 0.2.2 (24.12.2001):
novinyl-0.2.2.tar.gz (Source tarball)
Debian (sid) download page (Debian/unstable package)
Novinyl 0.1 (08.12.2001):
novinyl-0.1.tar.gz (Source tarball)

Using Novinyl to manage a list of KDE apps:

Novinyl data exported into KSpread (KOffice 1.1.1):

Copyright (C) 2001, 2002 Josef Spillner, dr_maux@users.sourceforge.net