These tabs are made up of local and external content. Tab 1 and Tab 2 are loading files tab1.html and tab2.html. Tab 3 and Another Tab are using content that is already part of this page.

First Tab

I'm the first tab and my content is local. Try clicking tab#2. It's loading remotely.
Tab 2

I am tab 3

Did you know that the children of a TabContainer can be any widget, such as a SplitContainer or LayoutContainer? The next tab is itself a TabContainer...

SubTab 1 SubTab 2