I was wondering if I could use the keyboard to navigate the tabs, and although there is such an intent in the code (https://github.com/aburch/simutrans/blob/0144db102df18c1e27208acad1e076b2a7a40753/src/simutrans/gui/components/gui_tab_panel.cc#L189), it doesn't seem to work right now.
Thank you. After some consideration, I chose TAB to change between tabs.
That seems appropriate 😛
It is not perfect, since if there is an edit field, the first tab always activate the edit field and only then the tabs are changing.
What about CTRL + TAB? I think this is what most browsers do for switching to the next tab (and CTRL+SHIFT+TAB for previous tab).