KAlarm is part of the KDE project http://www.kde.org from KDE 3.0 onwards, in the kdepim package. The main download site of the KDE project is ftp://ftp.kde.org/pub/kde/.

KAlarm is available for KDE 2 and as a standalone package for KDE3 from http://www.astrojar.org.uk/linux/kalarm.html