Here is short list of software and packages I had used for my projects:
The Visualization ToolKit (VTK) is an open source, freely available software system for 3D computer graphics, image processing, and visualization used by thousands of researchers and developers around the world.
Qt is a complete C++ application development framework. It includes a class library and tools for cross-platform development and internationalization.
ITK is an open-source software system to support the Visible Human Project. Currently under active development, ITK employs leading-edge segmentation and registration algorithms in two, three, and more dimensions.
An application designed with the need to visualize large data sets in mind.
Is an intuitive, interactive system for volume visualization that allows researchers and clinicians to quickly explore complex 3D medical or scientific images.
The Globus Project is developing fundamental technologies needed to build computational grids. Grids are persistent environments that enable software applications to integrate instruments, displays, computational and information resources that are managed by diverse organizations in widespread locations.