Physical sciences computing · CERN
ROOT
Open-source C++ data analysis framework built at CERN for processing and visualizing large particle-physics datasets.
ROOT is an open-source data analysis framework originally developed at CERN for the huge datasets produced by particle-physics experiments such as those at the Large Hadron Collider, and now used more broadly across physics, nuclear science and some other data-intensive research. It provides a columnar data format (TTree) optimized for scanning billions of events efficiently, statistical and fitting libraries, histogramming, and 2D/3D visualization, accessible through C++ or Python (PyROOT) interfaces. It underpins the software stacks of major LHC experiments and is maintained by CERN with contributions from the international physics community. Because it predates and outperforms general-purpose tools on physics-scale event data, it remains the default analysis framework in much of experimental particle physics despite growing competition from Python-native tools.
At a glance
| Vendor | CERN |
|---|---|
| Pricing model | Open source + paid options |
| Free tier | Yes |
| Deployment | Self-hosted |
| Open source | Yes (LGPL-2.1) |
| Best for | Particle and nuclear physicists processing and analyzing very large experimental event datasets. |
Pricing
Free and open source; developed and maintained by CERN.
Pricing has not been verified yet — see the vendor's site.
Features
- Columnar TTree data format for large event datasets
- C++ and Python (PyROOT) interfaces
- Statistical fitting and analysis libraries
- 2D/3D histogramming and visualization
- RDataFrame for parallel data processing
- Used by major LHC experiment software stacks
- Cross-platform (Linux, macOS, Windows)
Integrations
Profile last reviewed September 21, 2026