slackbuilds/desktop/avant-window-navigator

Avant Window Navigator (Awn)

Avant Window Navigator is a dock-like bar which sits at the bottom of
the screen. It has support for launchers, task lists, and third party
applets.

In order to handle transparencies that this application makes use of, you
MUST use a composite desktop manager and, of course, enable compositing.
Both KDE and XFCE from Slackware distro are composite capable.