Hi, As work from Gary about grouping windows has been integrated in 1.4, I try to use it for TWM. If you load: Gofer it squeaksource: 'TilingWindowManager'; package: 'TWM'; load. StandardWindow new addMorph: GroupWindowMorph new fullFrame: (LayoutFrame fractions: (0@0corner: 1@1 )); openInWorld. You can drag and drop windows in the GroupWindowMorph to tab them. But I cannot find why GroupWindowMorph does not fill all the window....... Gary ? Then I want to use GroupWindowMorph in a DockingBar. There's some initial work in DockingWindowMorph but I'm stuck with the space fill problem. Cheers, Laurent Laffont - @lolgzs <http://twitter.com/#!/lolgzs> Pharo Smalltalk Screencasts: http://www.pharocasts.com/ Blog: http://magaloma.blogspot.com/ Developer group: http://cara74.seasidehosting.st