普段は twm だけれど、ちょっと見栄えをよくしたい、気持ちを切り替えたい、 現実逃避をしたい、というときには WindowMaker がいいです。
~/GNUstep/Defaults/WMWindowAttributes
Kinput2 = { NoTitlebar = Yes; NoResizebar = Yes; NotClosable = Yes; NotMiniaturizable = Yes; KeepOnTop = Yes; Omnipresent = Yes; SkipWindowList = Yes; NoHideOthers = Yes; NoKeyBindings = Yes; NoMouseBindings = Yes; KeepInsideScreen = Yes; NoAppIcon = Yes; Unfocusable = Yes; DontSaveSession = Yes; };