SoQt is set of Qt GUI bindings for Coin library.

By using the combination of Coin, Qt and SoQt for your 3D applications,
you have a framework for writing completely portable software across the
whole range of UNIX, Linux, Microsoft Windows and Mac OS X operating
systems.  Coin, Qt and SoQt makes this possible from a 100% common
codebase, which means there is a minimum of hassle for developers when
working on multiplatform software, with the resulting large gains in
productivity.

SoQt, like Coin and Qt, provides the programmer with a high-level
application programmer's interface (API) in C++.  The library primarily
includes a class-hierarchy of viewer components of varying functionality
and complexity, with various modes for the end-user to control the
3D-scene camera interaction.