GpwTasklistA wrapper for WnckTasklist
GpwPagerA wrapper for WnckPager
GpwShowDesktopA GtkToggleAction based on libwnck providing the ability to show / hide the windows on the screen

These widgets are included only if gtk2panel has been built with libwnck support by explicitely using --enable-libwnck or leaving the default behaviour, that is let configure.ac check, having libwnck properly installed on the target system.