Publications

Overview contributions on ROOT

The ROOT Project: Status and Future Directions
Presentation WLCG/HSF Workshop 2024,
Authors: Danilo Piparo
Date: 15th May 2024
www: https://indico.cern.ch/event/1369601/contributions/5867782/

ROOT 6 and beyond - TObject, C++14 and many cores.
Conference 21st International Conference on Computing in High Energy and Nuclear Physics (CHEP2015) 13–17 April 2015, Okinawa, Japan,
Author: Bertrand Bellenot, Philippe Canal, Olivier Couet, Gerardo Ganis, Pere Mato Vila, Lorenzo Moneta, Axel Naumann and Danilo Piparo
Date: 23rd December 2015
doi: 10.1088/1742-6596/664/6/062006

ROOT - High Quality, Systematically
Conference International Conference on Computing in High Energy and Nuclear Physics 2012 (CHEP2012) 21–25 May 2012, New York, USA,
Author: Axel Naumann
Date: 13th December 2012
www: https://indi.to/hkQBX

ROOT overview
Conference International Conference on Computing in High Energy and Nuclear Physics 2012 (CHEP2012) 21–25 May 2012, New York, USA,
Author: Fons Rademakers
Date: 13th December 2012
www: https://indi.to/vZRYh

Design, Development and Evolution of the ROOT System
Conference 13th International Workshop on Advanced Computing and Analysis Techniques in Physics Research - ACAT 2010 Jaipur, India,
Author: René Brun, Philippe Canal and Fons Rademakers
Date: 22nd February 2010
www: https://pos.sissa.it/093/002/pdf

ROOT — A C++ framework for petabyte data storage, statistical analysis and visualization
Journal Computer Physics Communications Volume 180, Issue 12, December 2009, Pages 2499-2512,
Authors: Ilka Antcheva, Maarten Ballintijn, Bertrand Bellenot, Marek Biskup, René Brun, Nenad Buncic, Philippe Canal, Diego Casadei, Olivier Couet, Valeri Fine, Leandro Franco, Gerardo Ganis, Andrei Gheata, David González Maline, Masaharu Goto, Jan Iwaszkiewicz, Anna Kreshuk, Diego Marcos Segura, Richard Maunder, Lorenzo Moneta and Matevž Tadel
Date: 28th April 2009
doi: 10.1016/j.cpc.2009.08.005

ROOT - An Object-Oriented Data Analysis Framework.
Conference Proceedings AIHENP’96 Workshop, Lausanne, Sep. 1996, Nucl. Inst. & Meth. in Phys. Res. A 389 (1997) 81-86. See also https://root.cern/,
Authors: René Brun and Fons Rademakers
Date: 11th April 1997
doi: 10.1016/S0168-9002(97)00048-X
www: https://root.cern/download/lj.ps.gz
Note: Paper published in the Linux Journal, Issue 51, July 1998.

ROOT - An Interactive Object Oriented Framework and its application to NA49 data analysis
Conference Computing in High Energy Physics Berlin, Lichtenberger Congress Center, April 7-11, 1997,
Authors: René Brun, Nenad Buncic, Valeri Fine, Masaharu Goto, Fons Rademakers, Gunther Roland and Andres Sandoval
Date: 7th April 1997
www: https://root.cern/download/chep97_slides.tar.gz
Note: Slides of the presentation at CHEP'97 conference in Berlin.

ROOT contributions by topics

I/O

Development Status of RNtuple, the future HEP Columnar Storage Software Technology
Presentation WLCG/HSF Workshop 2024,
Authors: Danilo Piparo and Jakob Blomer
Date: 15th May 2024
www: https://indico.cern.ch/event/1369601/contributions/5867783/

ROOT for the HL-LHC - data format
Working-Paper arXiv,
Authors: Axel Naumann, Philippe Canal, Enric Tejedor Saavedra, Enrico Guiraud, Lorenzo Moneta, Bertrand Bellenot, Olivier Couet, Alja Mrak Tadel, Matevž Tadel, Sergey Linev, Javier López-Gómez, Jonas Rembser, Vincenzo Eduardo Padulano, Jakob Blomer, Jonas Hahnfeld, Bernhard Manfred Gruber and Vassil Vassilev
Date: 9th April 2022
doi: 10.48550/arXiv.2204.04557

RNTuple performance - Status and Outlook
Conference 20th International Workshop on Advanced Computing and Analysis Techniques in Physics Research (ACAT 2021),
Authors: Javier López-Gómez and Jakob Blomer
Date: 7th April 2022
doi: 10.48550/arXiv.2204.09043

Exploring Object Stores for High-Energy Physics Data Storage
Conference 25th International Conference on Computing in High Energy and Nuclear Physics (CHEP 2021),
Authors: Javier López-Gómez and Jakob Blomer
Date: 23rd August 2021
doi: 10.1051/epjconf/202125102066

ROOT I/O compression improvements for HEP analysis
Conference 24th International Conference on Computing in High Energy and Nuclear Physics (CHEP 2019) Adelaide, Australia, November 4-8, 2019,
Authors: Oksana Shadura, Brian Paul Bockelman, Philippe Canal, Danilo Piparo and Zhe Zhang
Date: 16th November 2020
doi: 10.1051/epjconf/202024502017

Evolution of the ROOT Tree I/O
Conference 24th International Conference on Computing in High Energy and Nuclear Physics (CHEP 2019) Adelaide, Australia, November 4-8, 2019,
Authors: Jakob Blomer, Philippe Canal, Axel Naumann and Danilo Piparo
Date: 16th November 2020
doi: 10.1051/epjconf/202024502030

Speeding HEP Analysis with ROOT Bulk I/O
Conference Journal of Physics - Conference Series, Volume 1525, 19th International Workshop on Advanced Computing and Analysis Techniques in Physics Research 11-15 March 2019, Saas-Fee, Switzerland,
Authors: B Bockelman, Z Zhang and Oksana Shadura
Date: 7th July 2020
doi: 10.1088/1742-6596/1525/1/012048

Writing ROOT Data in Parallel with TBufferMerger
Conference 23rd International Conference on Computing in High Energy and Nuclear Physics (CHEP 2018) Sofia, Bulgaria, July 9-13, 2018,
Authors: Guilherme Amadio, Philippe Canal, Enrico Guiraud and Danilo Piparo
Date: 17th September 2019
doi: 10.1051/epjconf/201921405037

ROOT I/O in JavaScript
Conference 20th International Conference on Computing in High Energy and Nuclear Physics (CHEP2013) 14–18 October 2013, Amsterdam, The Netherlands,
Authors: Bertrand Bellenot and Sergey Linev
Date: 11th June 2014
doi: 10.1088/1742-6596/513/5/052005

ROOT I/O in Javascript
Conference International Conference on Computing in High Energy and Nuclear Physics 2012 (CHEP2012) 21–25 May 2012, New York, USA,
Author: Bertrand Bellenot
Date: 13th December 2012
doi: 10.1088/1742-6596/396/5/052011

ROOT I/O Improvements
Conference International Conference on Computing in High Energy and Nuclear Physics 2012 (CHEP2012) 21–25 May 2012, New York, USA,
Author: Philippe Canal
Date: 13th December 2012
doi: 10.1088/1742-6596/396/5/052017

ROOT I/O - The Fast and Furious
Conference International Conference on Computing in High Energy and Nuclear Physics (CHEP 2010) 18–22 October 2010, Academia Sinica, Taipei, Taiwan,
Authors: Philippe Canal, Brian Bockelman and René Brun
Date: 23rd December 2011
doi: 10.1088/1742-6596/331/4/042005

Developments in ROOT I/O and trees
Conference INTERNATIONAL CONFERENCE ON COMPUTING IN HIGH ENERGY AND NUCLEAR PHYSICS (CHEP '07) 2–7 September 2007, Victoria, British Columbia, Canada,
Author: René Brun, Philippe Canal, Markus Frank, Anna Kreshuk, Sergey Linev, Paul Russo and Fons Rademakers
Date: 31st July 2008
doi: 10.1088/1742-6596/119/4/042006

RDataFrame

Prototyping a ROOT-based distributed analysis workflow for HL-LHC: the CMS use case
Journal Computer Physics Communications,
Authors: Tommaso Tedeschi, Vincenzo Eduardo Padulano, Daniele Spiga, Diego Ciangottini, Mirco Tracolli, Enric Tejedor Saavedra, Enrico Guiraud and Massimo Biasotto
Date: 16th October 2023
doi: 10.1016/j.cpc.2023.108965

Leveraging state-of-the-art engines for large-scale data analysis in High Energy Physics
Journal Journal of Grid Computing,
Authors: Vincenzo Eduardo Padulano, Ivan Donchev Kabadzhov, Enric Tejedor Saavedra, Enrico Guiraud and Pedro Alonso-Jordá
Date: 10th February 2023
doi: 10.1007/s10723-023-09645-2

Leveraging an open source serverless framework for high energy physics computing
Journal The Journal of Supercomputing,
Authors: Vincenzo Eduardo Padulano, Pablo Oliver Cortés, Pedro Alonso-Jordá, Enric Tejedor Saavedra, Sebastián Risco and Germán Moltó
Date: 2nd January 2023
doi: 10.1007/s11227-022-05016-y

A caching mechanism to exploit object store speed in High Energy Physics analysis
Journal Cluster Computing,
Authors: Vincenzo Eduardo Padulano, Enric Tejedor Saavedra, Pedro Alonso-Jordá, Javier López-Gómez and Jakob Blomer
Date: 14th October 2022
doi: 10.1007/s10586-022-03757-2

A Serverless Engine for High Energy Physics Distributed Analysis
Conference 22nd IEEE International Symposium on Cluster, Cloud and Internet Computing (CCGrid),
Authors: Jacek Kuśnierz, Vincenzo Eduardo Padulano, Maciej Malawski, Kamil Burkiewicz, Enric Tejedor Saavedra, Pedro Alonso-Jordá, Michael Pitt and Valentina Avati
Date: 16th May 2022
doi: 10.1109/CCGrid54584.2022.00067

Fine-grained data caching approaches to speedup a distributed RDataFrame analysis
Conference 25th International Conference on Computing in High Energy and Nuclear Physics (CHEP 2021),
Authors: Vincenzo Eduardo Padulano, Enric Tejedor Saavedra and Pedro Alonso-Jordá
Date: 23rd August 2021
doi: 10.1051/epjconf/202125102027

Distributed Parallel Analysis Engine for High Energy Physics Using AWS Lambda
Conference HiPS '21, Proceedings of the 1st Workshop on High Performance Serverless Computing,
Authors: Jacek Kuśnierz, Maciej Malawski, Vincenzo Eduardo Padulano, Enric Tejedor Saavedra and Pedro Alonso-Jorda
Date: 18th June 2021
doi: 10.1145/3452413.3464788

Distributed data analysis with ROOT RDataFrame
Conference 24th International Conference on Computing in High Energy and Nuclear Physics (CHEP 2019) Adelaide, Australia, November 4-8, 2019,
Authors: Vincenzo Eduardo Padulano, Javier Cervantes Villanueva, Enrico Guiraud and Enric Tejedor Saavedra
Date: 16th November 2020
doi: 10.1051/epjconf/202024503009

RDataFrame - Easy Parallel ROOT Analysis at 100 Threads
Conference 23rd International Conference on Computing in High Energy and Nuclear Physics (CHEP 2018) Sofia, Bulgaria, July 9-13, 2018,
Authors: Danilo Piparo, Philippe Canal, Enrico Guiraud, Xavier Valls Pla, Gerardo Ganis, Guilherme Amadio, Axel Naumann and Enric Tejedor Saavedra
Date: 17th September 2019
doi: 10.1051/epjconf/201921406029

Declarative Big Data Analysis for High-Energy Physics, TOTEM Use Case
Conference Euro-Par 2019, Parallel Processing pp 241–255,
Authors: Valentina Avati, Milosz Blaszkiewicz, Enrico Bocchi, Luca Canali, Diogo Castro, Javier Cervantes, Leszek Grzanka, Enrico Guiraud, Jan Kaspar, Prasanth Kothuri, Massimo Lamanna, Maciej Malawski, Aleksandra Mnich, Jakub Moscicki, Shravan Murali, Danilo Piparo and Enric Tejedor Saavedra
Date: 13th August 2019
doi: 10.1007/978-3-030-29400-7_18

Novel functional and distributed approaches to data analysis available in ROOT
Conference Journal of Physics, Conference Series, Volume 1085, Issue 4,
Authors: Guilherme Amadio, Jakob Blomer, Philippe Canal, Gerardo Ganis, Enrico Guiraud, Pere Mato Vila, Lorenzo Moneta, Danilo Piparo, Enric Tejedor Saavedra and Xavier Valls Pla
Date: 21st August 2017
doi: 10.1088/1742-6596/1085/4/042008

TMVA, ML

C++ Code Generation for Fast Inference of Deep Learning Models in ROOT/TMVA
Conference 25th International Conference on Computing in High Energy and Nuclear Physics (CHEP 2021),
Authors: Sitong An and Lorenzo Moneta
Date: 23rd August 2021
doi: 10.1051/epjconf/202125103040

Machine Learning with ROOT/TMVA
Conference 24th International Conference on Computing in High Energy and Nuclear Physics (CHEP 2019) Adelaide, Australia, November 4-8, 2019,
Authors: Kim Albertsson, Sitong An, Sergei Gleyzer, Lorenzo Moneta, Joana Niermann, Stefan Wunsch, Luca Zampieri and Omar Andres Zapata Mesa
Date: 16th November 2020
doi: 10.1051/epjconf/202024506019

Machine Learning with ROOT/TMVA
Conference 22nd International Conference on Computing in High Energy and Nuclear Physics (CHEP2016) 10–14 October 2016, San Francisco, USA,
Authors: A Bagoly, A Bevan, A Carnes, S V Gleyzer, Lorenzo Moneta, A Moudgil, S Pfreundschuh, T Stevenson, Stefan Wunsch and O Zapata
Date: 23rd November 2017
doi: 10.1088/1742-6596/898/7/072046

Development of Machine Learning Tools in ROOT
Conference 17th International Workshop on Advanced Computing and Analysis Techniques in Physics Research (ACAT2016) 18–22 January 2016, Valparaíso, Chile,
Authors: S. V. Gleyzer, Lorenzo Moneta and Omar A. Zapata
Date: 21st November 2016
doi: 10.1088/1742-6596/762/1/012043

RooFit

Faster RooFitting - Automated parallel calculation of collaborative statistical models
Conference 24th International Conference on Computing in High Energy and Nuclear Physics (CHEP 2019) Adelaide, Australia, November 4-8, 2019,
Authors: E G Patrick Bos, Carsten D Burgard, Vincent A. Croft, Stephan Hageboeck, Lorenzo Moneta, Inti Pelupessy, Jisk J Attema and Wouter Verkerke
Date: 16th November 2020
doi: 10.1051/epjconf/202024506027

A Faster, More Intuitive RooFit
Conference 24th International Conference on Computing in High Energy and Nuclear Physics (CHEP 2019) Adelaide, Australia, November 4-8, 2019,
Author: Stephan Hageboeck
Date: 16th November 2020
doi: 10.1051/epjconf/202024506007

The RooStats project
Conference 13th International Workshop on Advanced Computing and Analysis Techniques in Physics Research (ACAT2010),
Authors: Lorenzo Moneta, K. Cranmer, G. Schott and W. Verkerke
Date: 24th February 2011
doi: 10.22323/1.093.0057

Recent developments of the ROOT mathematical and statistical software
Conference INTERNATIONAL CONFERENCE ON COMPUTING IN HIGH ENERGY AND NUCLEAR PHYSICS (CHEP '07) 2–7 September 2007, Victoria, British Columbia, Canada,
Author: Lorenzo Moneta, Ilka Antcheva and René Brun
Date: 31st July 2008
doi: 10.1088/1742-6596/119/4/042023

Cling / C++

C++ Modules in ROOT and Beyond
Conference 24th International Conference on Computing in High Energy and Nuclear Physics (CHEP 2019) Adelaide, Australia, November 4-8, 2019,
Authors: Vassil Vassilev, David Lange, Malik Shahzad Muzaffar, Mircho Rodozov, Oksana Shadura and Alexander Penev
Date: 25th August 2020
doi: 10.48550/arXiv.2004.06507

Migrating large codebases to C++ Modules
Conference Journal of Physics - Conference Series, Volume 1525, 19th International Workshop on Advanced Computing and Analysis Techniques in Physics Research 11-15 March 2019, Saas-Fee, Switzerland,
Authors: Y Takahashi, Oksana Shadura and Vassil Vassilev
Date: 7th July 2020
doi: 10.1088/1742-6596/1525/1/012051

Relaxing the one definition rule in interpreted C++
Conference Proceedings of the 29th International Conference on Compiler Construction February 2020 Pages 212–222,
Authors: Javier López-Gómez, Javier Fernández, David del Rio Astorga, Vassil Vassilev, Axel Naumann and J. Daniel García
Date: 16th December 2019
doi: 10.5281/zenodo.3579301

Optimizing ROOT’s Performance Using C++ Modules
Conference Journal of Physics - Conference Series, Volume 898, Track 5 - Software Development,
Author: Vassil Vassilev
Date: 23rd November 2017
doi: 10.1088/1742-6596/898/7/072023

Clad — Automatic Differentiation Using Clang and LLVM
Conference Journal of Physics - Conference Series, Volume 608, 16th International workshop on Advanced Computing and Analysis Techniques in physics research (ACAT2014) 1–5 September 2014, Prague, Czech Republic,
Authors: Vassil Vassilev, M. Vassilev, A. Penev, Lorenzo Moneta and V. Ilieva
Date: 22nd May 2015
doi: 10.1088/1742-6596/608/1/012055

Cling – The New Interactive Interpreter for ROOT 6
Conference International Conference on Computing in High Energy and Nuclear Physics 2012 (CHEP2012) 21–25 May 2012, New York, USA,
Authors: Vassil Vassilev, Philippe Canal, Axel Naumann and Paul Russo
Date: 13th December 2012
doi: 10.1088/1742-6596/396/5/052071

Preparing for the new C++11 standard
Conference International Conference on Computing in High Energy and Nuclear Physics 2012 (CHEP2012) 21–25 May 2012, New York, USA,
Author: Axel Naumann
Date: 13th December 2012
doi: 10.1088/1742-6596/396/5/052056

Visualization

EVE-7 and FireworksWeb - The next generation event visualization tools for ROOT and CMS
Conference 24th International Conference on Computing in High Energy and Nuclear Physics (CHEP 2019) Adelaide, Australia, November 4-8, 2019,
Authors: Alja Mrak Tadel, Matevž Tadel, Avi Yagil, Dmytro Kovalskyi and Sergey Linev
Date: 16th November 2020
doi: 10.1051/epjconf/202024508027

New ROOT graphics language
Conference Journal of Physics Conference Series 1525(1):012061,
Authors: Iliana Betsou, Sergey Linev, Bertrand Bellenot and Olivier Couet
Date: 11th March 2019
doi: 10.1088/1742-6596/1525/1/012061

The Rainbow color map
Working-Paper ResearchGate,
Author: Olivier Couet
Date: 23rd September 2013
www: https://www.researchgate.net/publication/273761444_The_Rainbow_color_map

New ROOT Graphical User Interfaces for fitting
Conference 17th International Conference on Computing in High Energy and Nuclear Physics (CHEP09) 21–27 March 2009, Prague, Czech Republic,
Author: David González Maline, Lorenzo Moneta and Ilka Antcheva
Date: 7th May 2010
doi: 10.1088/1742-6596/219/4/042010

Overview of EVE – the event visualization environment of ROOT
Conference 17th International Conference on Computing in High Energy and Nuclear Physics (CHEP09) 21–27 March 2009, Prague, Czech Republic,
Author: Matevž Tadel
Date: 7th May 2010
doi: 10.1088/1742-6596/219/4/042055

The new generation of OpenGL support in ROOT
Conference INTERNATIONAL CONFERENCE ON COMPUTING IN HIGH ENERGY AND NUCLEAR PHYSICS (CHEP '07) 2–7 September 2007, Victoria, British Columbia, Canada,
Author: Matevž Tadel
Date: 31st July 2008
doi: 10.1088/1742-6596/119/4/042028

Multiple variables data sets visualization in ROOT
Conference INTERNATIONAL CONFERENCE ON COMPUTING IN HIGH ENERGY AND NUCLEAR PHYSICS (CHEP '07) 2–7 September 2007, Victoria, British Columbia, Canada,
Author: Olivier Couet
Date: 31st July 2008
doi: 10.1088/1742-6596/119/4/042007

The graphics editor in ROOT
Conference X International Workshop on Advanced Computing and Analysis Techniques (ACAT 05),
Authors: Ilka Antcheva, René Brun, Carsten Hof and Fons Rademakers
Date: 22nd May 2005
doi: 10.1016/j.nima.2005.11.113

The ROOT geometry package
Conference Proceedings of the VIII International Workshop on Advanced Computing and Analysis Techniques in Physics Research (ACAT 2002) • Moscow, Russia,
Authors: René Brun, Andrei Gheata and M.Gheata
Date: 22nd June 2002
doi: 10.1016/S0168-9002(03)00541-2

Parallelism

A Parallelised ROOT for Future HEP Data Processing
Conference 23rd International Conference on Computing in High Energy and Nuclear Physics (CHEP 2018) Sofia, Bulgaria, July 9-13, 2018,
Authors: Danilo Piparo, Philippe Canal, Guilherme Amadio, Enrico Guiraud, Axel Naumann, Xavier Valls and Enric Tejedor Saavedra
Date: 17th September 2019

Expressing Parallelism with ROOT
Conference Journal of Physics - Conference Series, Volume 898, Track 5 - Software Development,
Authors: Danilo Piparo, Enric Tejedor Saavedra, Enrico Guiraud, Gerardo Ganis, Pere Mato Vila, Lorenzo Moneta, Xavier Valls Pla, and Philippe Canal
Date: 23rd November 2017
doi: 10.1088/1742-6596/898/7/072022

PEAC - A set of tools to quickly enable PROOF on a cluster
Conference International Conference on Computing in High Energy and Nuclear Physics 2012 (CHEP2012) 21–25 May 2012, New York, USA,
Authors: Gerardo Ganis and Martin Vala
Date: 13th December 2012
doi: 10.1088/1742-6596/396/3/032044

The PROOF Distributed Parallel Analysis Framework based on ROOT
Conference 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, CA, USA, March 2003,
Authors: Maarten Ballintijn, René Brun, Fons Rademakers and Gunther Roland
Date: 13th June 2003
doi: 10.48550/arXiv.physics/0306110

CINT

CINT was the C++ interpreter until ROOT version 5. In case you want to cite CINT, use the following references:

C++ Interpreter - CINT
Journal CQ publishing, ISBN4-789-3085-3 (Japanese),
Author: Masaharu Goto
Date: 14th October 2002
www: https://root.cern/download/R2002/Cint2002.pdf

Learning C++ with CINT
Journal C magazine 1998 Apr-1999 Mar, Softbank Co, (Japanese),
Author: Masaharu Goto
Date: 1st April 1998

BeOS and ROOT
Journal Interface magazine 1997 Sep, CQ publishing, (Japanese),
Author: Masaharu Goto
Date: 1st September 1997

Cint - embedding Tcl/Tk graphics
Journal Interface magazine 1997 Feb, CQ publishing, (Japanese),
Author: Masaharu Goto
Date: 1st February 1997

Concept and application of Cint C++ interpreter
Journal Interface magazine 1996 Aug-Nov, CQ publishing, (Japanese),
Author: Masaharu Goto
Date: 1st August 1996

Evaluating query languages and systems for high-energy physics data
Journal Proceedings of the VLDB Endowment Volume 15 Issue 2 October 2021 pp 154–168,
Authors: Dan Graur, Ingo Müller, Mason Proffitt, Ghislain Fourny, Gordon T. Watts and Gustavo Alonso
Date: 4th February 2022
doi: 10.14778/3489496.3489498

An Exhibition Booth for demonstrating recent developments in data processing software used at the LHC
Conference International Conference on Computing in High Energy and Nuclear Physics 2012 (CHEP2012) 21–25 May 2012, New York, USA,
Author: John Harvey
Date: 13th December 2012
www: https://indi.to/3vYGk

The Cathedral and the Bazaar
Author: Eric S. Raymond
Date: 1st January 1999
www: https://en.wikipedia.org/wiki/The_Cathedral_and_the_Bazaar
Note: The “Bazaar” software development process we tried to follow.

The Power of Object Oriented Frameworks
Journal Interface magazine, CQ publishing,
Author: Fons Rademakers
Date: 1st January 1997
www: https://root.cern/download/frameworks.ps.gz

Microkernel vs Monolithic System
Authors: Linus Torvalds and Andy Tanenbaum
Date: 29th January 1992
www: https://en.wikipedia.org/wiki/Tanenbaum–Torvalds_debate
Note: Famous discussion between Linus Torvalds and Andy Tanenbaum on the merits of these two approaches. ROOT is often seen, like Linux, as a monolithic system. Both are not doing too bad.