ROOT

ROOT is a data management program developed by CERN. It includes histograms, curve fitting, function evaluation, minimization, graphics and visualization classes to simplify the analysis of data, both interactively and in batch mode. It also includes a speedy general parallel processing framework, PROOF.

ROOT is used in the fields of physics, finance, medicine, biology, and astronomy.

C++ implementation
ROOT implements a built-in CINT C++ interpreter; and all of the commands, scripts, and programs are in C++. ROOT also uses object-oriented programming (OOP) with C++, which is programming with objects.

Other
ROOT allows for linking external libraries. Therefore, ROOT can build data acquisition, simulation and data analysis systems.

Links/Sources
About ROOT- http://root.cern.ch/drupal/content/about

Data Analysis & Visualization- ROOT: http://root.cern.ch/drupal/category/image-galleries/data-analysis-visualization