Sideways tabs should not be used in any program.
I know it kinda looks cool or saves horizontal space, relatively to a layout with the same tabs in the same place with an horizontal text instead, but this is a *BAD* navigation technique.
At least, it should be off by default, or the user should be able to get rid of every vertical text in the entire IDE if he wants to.

Human beings read from left to right, not from bottom to top with rotated text.

Here is a reference to this problem:
http://www.youtube.com/watch?v=pBJXggsYfMk
This boils down to this:
"Maybe young girls like to look at things sideways.. I don't think so, but I can be wrong."

I think that another problem is that this navigation technique is used inside an IDE, a tool used by various developers, and some of them don't necessarily have any knowledge of UI design.
So this tends to legitimate the usage of sideways tabs.
It is also used by default in Kate, but fortunately you can set the tab to be displayed at the bottom.

--
al

Without an idea how to do it better this is sort of theoretical. You can't display tabs on the bottom and then open up a toolview on the left if they're clicked.

Also, UI design theory in honours, but this works perfectly fine for me. It's not like you'd have to read the text on the tabs, you'll know which tab is which by the icon after you used the IDE for a few days.

Greetings

I know that Amarok has had this discussion a few times (it used to have sideway "tabs" as well). alecail, do you have any suggestions what to replace them with? A mockup would be cool.