1) Insight Segmentation and Registration Toolkit (ITK).
2) The Visualization ToolKit (VTK).
3) Cross-Platform GUI Library (wxWidgets).
4) Parallel Visualization Application (ParaView).
5) Image Processing and Analysis in Java (ImageJ).
6) GNU Octave (Octave).
7) The GNU Compiler Collection (GCC).
8) KDE Development Environment (KDevelop).
9) Dynamic Analysis Tool for debugging and profiling
Linux programs (Valgrind).