Previous Developers

The following people have been working on ROOT for some time in their career and ROOT would not be what it is without their contributions:

Axel Naumann

Starting off as a physicist, Axel studied physics and math in Muenster, Germany. In 2000, he got a Ph.D. position for high energy physics in Nijmegen, The Netherlands. They sent him to Fermilab at Chicago, where he worked with the DØ experiment - which also meant writing software from PCI drivers to data analysis code. During that time he got involved with ROOT, converting from a user to a developer. He contributed to whatever he needed, e.g. the statistics part, the documentation engine, and porting it to cygwin. After a position with the Fermilab Computing Division in 2005 he ended up at CERN in the ROOT development team. Axel led the ROOT project from 2017 to 2023.

Andrei Gheata

Andrei works since 2001 in the offline group of the ALICE experiment. He is an experimental nuclear physicist who worked before ALICE on data analysis for heavy-ion experiments in emulsions. In 2000 he started collaborating with the ROOT project and implemented the TreeViewer interface. Andrei is the main developer of the ROOT geometry package. He integrated the geometry in the Virtual Monte Carlo framework by developing interfaces for the GEANT3, GEANT4 and FLUKA particle transport engines.

Anna Kreshuk

Anna was a project associate and contributed to different parts of ROOT, most notably to the fitting machinery, the interface to FFTW, numerous math-related functions, TEntryList container and PROOF GUI.

David González Maline

David has been working on improving the performance and correctness of various mathematical algorithms as well as on integrating AI methods for data analysis inside the framework. He has also worked on extending and improving the FitPanel interface.

Diego Marcos Segura

Diego worked as technical student on CINT dictionary optimizations.

Eddy Offermann

Eddy joined the ROOT team during a sabbatical to work on making the ROOT matrix package the fastest and most versatile in the industry.

Ilka Antcheva

Ilka has been working from 2002 to 2008 in the ROOT team. She was responsible for the GUI system and designed many high level user interfaces and widgets, like found in many modern graphics applications: ROOT graphics editor (GED) and various object editors, Fit Panel, Style manager, a tool for automatic C++ code generation of any widget and the capability for widgets to save themselves. In addition Ilka took care of the ROOT Users Guide and contributed the chapter ‘Writing a Graphical User Interface’.

Gerardo Ganis

Gerri was a team member for more than ten years; among many other contributions he was in charge of PROOF for many years.

Guilherme Amadio

Guilherme has always been at the interface between physics and computer science. He started his undergraduate studies in computer science at the University of São Paulo (USP) campus in São Carlos in 2000, but later moved to the São Paulo campus for the course of molecular sciences, a special interdisciplinary program of the university aimed at preparing students for scientific research. In 2004, he moved to Japan for his master degree in nuclear physics at the University of Tokyo, where he studied the elastic and inelastic scattering of ⁷Be+p. He then moved on to obtain his PhD in aerospace engineering from the University of Illinois at Urbana-Champaign, USA. Guilherme then worked for two years at São Paulo State University (UNESP) in collaboration with CERN and Fermilab before joining the ROOT Team in April of 2017. His responsibilities in ROOT include working on the build system, performance analysis and optimization, and support for SIMD vectorization.

Jan Iwaszkiewicz

Jan was working in the context of a Ph.D. on scheduling and load- balancing of distributed processing in the Parallel ROOT Facility (PROOF).

Leandro Franco

Leo worked a Marie-Curie fellow in the ROOT team from 2005-2008. He worked on a number of widely different topics, from parallel sockets, I/O read-ahead, CINT dictionary, etc.

Maarten Ballintijn

Maarten's initial dab into ROOT was porting it to Linux in 1995. Later he worked on the PROOF system, bringing into production for the RHIC experiments in Brookhaven.

Marek Biskup

Marek worked as technical student on various aspects of PROOF, notably integrating the TChain::Draw() command into PROOF.

Masaharu Goto

Masa is the father of CINT. Without the indefatigable support by Masa we would never have succeeded with the tight integration of CINT in ROOT. Masa is now managing a large division in Agilent and cannot spend as much time on CINT as he would like.

Matevž Tadel

Matevž Tadel is the main developer of 3D graphics and event-visualization packages. He holds a Ph.D. in experimental high-energy physics, obtained in 2001 for his work on electron reconstruction in the ATLAS experiment. Before joining the ROOT team in 2005, he worked on Gled - an advanced ROOT-based system for distributed computing and dynamic visualisation.

Nenad Buncic

Nenad was one of the first people joining the initial ROOT team in 1996. He developed the first version of the HTML documentation system (THtml) and worked on the first version of the 3D graphics system. Nenad left in 1997.

Paul Russo

Paul joined the ROOT team at Fermilab in 2005 and has been focusing on support and developing CINT.

Pere Mato Vila

Pere Mato Vila was the project leader from 2014 to 2017. He was the driving force behind ROOT's migration to CMake and has contributed to PyROOT.

Richard Maunder

Richard worked as project associate on the 3D graphics OpenGL based system.

Oksana Shadura

Currently, I am employed as a software developer from the University of Nebraska-Lincoln (CMS), based at CERN and working as a core developer in the ROOT framework. My area of research is a various improvement for ROOT I/O, particularly ROOT compression algorithms. Another area of investigation is work on improved ROOT modularity for the build system. I was involved in support of C++ modules in ROOT and performance benchmarking of ROOT. I did my doctoral studies in Simulation group at CERN, working in GeantV project (EP-SFT, CERN). Previous work experience was a long term work in Ukrainian Grid Initiative on various positions, including responsibilities on grid sites management and experiment support, administration, and security management.

Stephan Hageboeck

Stephan is a particle physicist, and obtained his Ph.D. at the university of Bonn in Germany. He worked in ATLAS to improve the sensitivity in the search for Higgs --> bb decays. His main focus was on analysis frameworks, machine learning, systematic uncertainties and statistical models. He joined the ROOT team in 2018 to support and improve RooFit. He further looks into math and statistics, as well as into questions regarding performance and programming model.

Susan Panacek

Susan wrote the first ROOT User's Guide and developed a number of ROOT tutorials.

Enric Tejedor Saavedra

Enric Tejedor Saavedra received his Ph.D. from the Technical University of Catalonia (UPC, Spain) in 2013. He conducted his doctorate research as a member of the Grid Computing and Clusters group of the Barcelona Supercomputing Center, where his researched focused on parallel programming models for distributed infrastructures and where he participated in several EU research projects. As part of his Ph.D., he also carried out two internships at the IBM T.J. Watson Research Center (NY, USA). In 2015 he joined the CERN EP-SFT group as a senior fellow and later became a staff member. He is currently working on ROOT parallelization, the ROOT Python bindings and the SWAN service. He is also one of the administrators of the Google Summer of Code student program (GSoC) at CERN-HEP Software Foundation.

Timur Pocheptsov

Timur worked as a project associate on many different aspects of ROOT, but mostly on the OpenGL accelerated 3D graphics and the native macOS Cocoa based GUI. Timur also ported ROOT to the iPad. He continues to maintain the OpenGL and Cocoa code till this day.

Valeri Fine

Valeri was a member of the ROOT team from 1998-2000. He made the initial port to Windows. Currently he is the maintainer of the ROOT-Qt interface.

Valeri Onuchin

Valeri worked as a project associate on many different aspects of ROOT, but mostly in the GUI and graphics area. He did develop the signal/slot functionality and the GUI builder. He also developed the Carrot ROOT enabled web server.

Stefan Wunsch

Stefan studied physics at the Karlsruhe Institute of Technology with focus on data analysis, machine learning and software development. Previous projects have been with the Belle and CMS experiments about the integration of modern machine learning in the reconstruction and data analysis toolchain. After his first stay at CERN in 2016 as summer student with the CMS experiment, he returned to CERN in 2018 as PhD working in the ROOT team on machine learning and analysis facilities.

Javier López-Gómez

Javier is a computer scientist from University Carlos III of Madrid. His Ph.D. thesis focused on providing techniques that improve software reliability while achieving a good trade-off between reliability and performance. During his PhD, he collaborated with the ROOT project; specifically, he worked on supporting entity redefinition on the Cling C++ interpreter. As a fellow of the EP-SFT group he improved ROOT's RNtuple storage layer.