"QextMDI is a library that extends the Qt 2.x library from
Troll Tech to provide support for several modes of MDI
Why Highlighted: Whether you love or hate
MDI-style interfaces, there are definitely situations where they're
useful and appreciated by users. QextMDI adds them to Qt 2.x, and
provides two variations of GUI treatment, with two more (tabbed
interface and split windows) in the works.