dtscreen

The modes give away the origin: qix, flame, pyro, swarm, worm, hop, life, rotor, blank and image are xlock's repertoire from Patrick Naughton's days at Sun, and the source still carries his copyright lines. The difference is the architecture. xlock locked and animated in one process; in CDE dtscreen only draws, while dtsession watches for idleness, starts the saver, kills it at the first keystroke and alone shows the password dialog if locking is on. It is the same separation Jamie Zawinski later argued for in XScreenSaver.

Each mode was an action in the database, StartDtscreenQix and so on, and the resource dtsession*saverList enumerated which ones were allowed to run. Users picked them in dtstyle's Screen dialog, with time until start, time per saver and whether the screen should lock as well. An administrator who wanted something more entertaining defined a Start action of their own pointing at any program and added it to the list, which is how xlockmore and XScreenSaver's hacks were smuggled into many CDE installations.