The Visualization Toolkit (VTK) is an open-source, freely available software system for 3D computer graphics, image processing and visualization. VTK consists of a C++ class library and several interpreted interface layers including Tcl/Tk, Java, and Python.
The Internet Communications Engine (Ice) is a modern object-oriented middleware with support for C++, .NET, Java, Python, Objective-C, Ruby, and PHP. Ice is used in many mission-critical projects by companies all over the world. Ice is easy to learn, yet provides a powerful network infrastructure and vast array of features for demanding technical applications. Ice is free software, available with full source, and released under the terms of GNU General Public License (GPL). Commercial licenses are available for customers who wish to use Ice for closed-source software.