I submitted the idea, however, I cannot wait until a future release to add tab spacing.  Since I have the source, how can I do it myself?  With some guidance, I should be able to expose the property through the managers.  At the end, all I need to do is set the property UltraTabControlBase.InterTabSpacing in all tabs, but I need a way to get to the tabs from the managers.

DockManager and TabbedMdiManager do not use UltraTabControlBase. That only applies to UltraTabControl or UltraTabStrip. 

If you are looking for the shared code that handles the tabs for all of these controls, what you want is the TabManager. 

DockManager creates 2 classes derived from TabManager:

GroupTabManager and UnpinnedTabManager. 

GroupTabManager is probably the one you want here. But you could override InterTabSpacing for one or both of these classes if you intend to rebuild the control's source. 

For TabbedMdi, it looks like the TabManager-derived class is called MdiTabGroupManager.

Just FYI, though... if you are going to modify the source code like this, we can't really make any guarantees that this will work. I THINK the TabManager is probably smart enough to account for the InterTabSpacing if you simply override it on these classes and return a value. But it's also possible that something in the control's or components here is just assuming that the InterTabSpacing is always going to be the default. So I would not be too surprised if changing the InterTabSpacing caused some other UIElement to be positioned incorrectly, overlap, or be missing. So this is a use-at-your-own-risk scenario.

Just off the top of my head, I'd say your odds of it working are pretty good, though. 

Mike, overriding InterTabSpacing in GroupTabManager did the trick.  Thank you.  I am now getting the space between the tabs that I need.  There is more thing.  I found that that you can set padding in the UltraToolsManager.  I am setting UltraToolsManager.ToolbarSettings.PaddingBottom.  I will like to set left and right padding on the DockManager.  Is that possible?  I am only showing icons on the tabs.  I have them dock to the left and right. They are too close to the edge and I will like more padding, but I have not figure out how to do that.

Hi, 

I'm not sure I understand what you are asking, exactly. Can you maybe post a screen shot? 

I assume you are referring to UltraToolbarsManager here, because I'm not familiar with any UltraToolsManager. The padding of UltraToolbarsManager wouldn't have any relation to UltraDockManager. 

It sounds like you want the dock panes on the right and left to not go right up to the edge of the form? 
I can't think of any way to do that. Unless maybe you put the DockManager into a UserControl instead of on the form. Then you could place the UserControl on the form and arrange it so that it doesn't go all the way to the left and right edge of the form. Not sure what ramifications that might have on your application.