Your comments

I think this should be in a new thread.

I think Abu Imir has a large number of tabs (i.e., hundreds), and complexly nested trees. He seems to want to move tabs between two arbitrary locations with ease, IIRC from another thread.

An alternative fix would be to create another icon in the Reddit/Notepad area for an extra tree list. Then, the user would simply drag and drop the tab(s)/tree(s) from List 1 to List 2. (Note that List 1 and List 2 are the same tab list, just in different scrollbar positions.)

This is similar to how Tabs Outliner does it. (Except Tabs Outliner duplicates itself and creates two panels.)

Looking at this again (after getting used to Sidewise), if it's a hack to implement the 'auto-tree bookmarks' behavior, then don't bother. I hadn't realized I could shift-select tabs to rearrange them.

I was wondering, how do you plan on fixing the "too many children" problem? As you said, it's hard to tell if Chrome is opening bookmarks. Perhaps a "Flatten Tree" option, if the fix is still a hack?

On Windows 7, I still have the alt-tab problem when cycling Chrome/Sidewise are open in the background.

Unfortunately, it only allows for substring matches... therefore, if I have any tab open which contains the text "Sidewise" (for example, this page), then the Chrome window is removed from the taskbar.

Also, alt-tabbing is still a problem for me if I have the Chrome/Sidewise window open.

Nevertheless, nice find.

This should be a menu option, but not default behavior.

Implementation? Maybe collapsing older trees after a threshold of trees are expanded or simply collapsing inactive trees after a set period of time?

Nope; I'd rather quickly and temporarily switch between the two rather than have to use a right-click menu to enable/disable this.