Release 6.18/00 - 2019-06-25


ROOT v6.18/00 is a consolidation release with many performance improvements! Its more than 2000 commits since v6.16/00 also introduce several new features:

  • A new builtin zlib library that’s based on CMS’s fork of the Cloudflare implementation. It noticeably accelerates decompression on current CPUs.
  • A simple auto obj = dir->Get<MyClass>("some object"); (where dir can be a file)
  • Pythonizations for RDataFrame providing AsNumPy
  • New leaf types /f, /d for Float16_t and Double32_t: tree->Branch("floatArray", floatArray, "floatArray[7]/f[0,100]"); // Float16_t array with range from 0 to 100
  • Several new functions for RVec, e.g. DeltaR
  • The RooJohnson PDF was added to RooFit
  • Considerably faster, STL-style iteration through RooArgSet and RooArgList
  • Transparency for lines, texts and markers in the TeX output.
  • Many new features in JSROOT, including initial WebVR support thanks to Diego Marcos (get your Cardboards ready!)
  • Added support for GCC9, macos 10.15 (Catalina beta 2) and Xcode 11.0 beta

If you build against ROOT using its CMake infrastructure you might be interested in the changes to ROOT_GENERATE_DICTIONARY and ROOT_STANDARD_LIBRARY_PACKAGE. For this and what else is new please have a look at the release notes!

Release Notes

The release notes for this release can be found here.

Source distribution

Platform Files Size
source root_v6.18.00.source.tar.gz 158M

Binary distributions

Platform Files Size
CentOS Cern 7 gcc4.8 root_v6.18.00.Linux-centos7-x86_64-gcc4.8.tar.gz 137M
Linux fedora29 gcc8.3 root_v6.18.00.Linux-fedora29-x86_64-gcc8.3.tar.gz 155M
Linux fedora30 gcc9.1 root_v6.18.00.Linux-fedora30-x86_64-gcc9.1.tar.gz 158M
Ubuntu 14 gcc4.8 root_v6.18.00.Linux-ubuntu14-x86_64-gcc4.8.tar.gz 137M
Ubuntu 16 gcc5.4 root_v6.18.00.Linux-ubuntu16-x86_64-gcc5.4.tar.gz 144M
Ubuntu 18 gcc7.4 root_v6.18.00.Linux-ubuntu18-x86_64-gcc7.4.tar.gz 153M
OsX 10.13 clang100 root_v6.18.00.macosx64-10.13-clang100.dmg 130M
OsX 10.13 clang100 root_v6.18.00.macosx64-10.13-clang100.tar.gz 129M
OsX 10.14 clang100 root_v6.18.00.macosx64-10.14-clang100.dmg 131M
OsX 10.14 clang100 root_v6.18.00.macosx64-10.14-clang100.tar.gz 130M

Example for setting up ROOT from CVMFS

. /cvmfs/


The entire ROOT source can be obtained from our public Git repository:

git clone

The release specific tag can be obtained using:

cd root
git checkout -b v6-18-00 v6-18-00


Windows 7/Vista/XP/NT/2000 are supported. We offer two packaging types:

  • exe: a regular Windows installer package also setting up the required environment variables. With uninstall via “Control Panel” / “Add or Remove Programs”. Simply download and start, or open directly. You can double-click ROOT to start it, ROOT files get registered with Windows.
  • tar: the traditional variant. Unpack e.g. with 7zip. Start ROOT in a Microsoft Visual Studio Prompt (in Start / Programs / Microsoft Visual Studio / Tools). If you installed ROOT to C:\root then call C:\root\bin\thisroot.bat before using ROOT to set up required environment variables.

Important installation notes

  • You must download the binary built with the exact same version of Visual Studio as the one installed on your system.
  • Do not untar in a directory with a name containing blank characters.
  • Take the release version if performance matters.
  • If you want to debug your code you need the ROOT debug build (you cannot mix release / debug builds due to a Microsoft restriction).