50 years GSI



The new accelerator facility FAIR is under construction at GSI. Learn more.


GSI is member of


Funded by




The Go4 Project page

Latest release: Go4 Version 5.3.2 (October 26th, 2018):

  supports ROOT 6 and Qt3/Qt4/Qt5 for Linux and Windows 7/8

  HTTP Server and improved web browser GUI

  Python scripting in analysis and GUI

  new: user defined command buttons in GUI, high DPI support


  • Sourcecode browser (doxygen)  (html)

Old version: v4.7.0 with Qt3/Qt4 on Linux, Windows XP/7, and MacOS X support  (October 17th 2014)

Enable Go4 environment at GSI linux:

. /cvmfs/csee.gsi.de/bin/go4login 

     (enables most recent Go4 Version)

. /cvmfs/csee.gsi.de/bin/go4login <versiontag>

     (enables version by number, e.g. 501-02)

. /cvmfs/csee.gsi.de/bin/go4login -h 

    (shows list of installed Go4 versions)


What is Go4?

The object-oriented system Go4 (GSI Object Oriented On-line Off-line system)  is based on ROOT (R. Brun et al.) with the specific requirements of the low and medium energy nuclear and atomic physics experiments implemented as extensions.

Go4separates analysis and GUI in two tasks which could run on different nodes. Communication is done through threads and sockets. The GUI is built with the Qt widget library using the Qt designer. Qt and ROOT are interfaced by QtROOT. Full ROOT functionality including menus and graphics is available without modifications. The Go4 analysis framework provides the syntax to organize the analysis in steps which can be controlled from the GUI. Each step has its own IO and processing classes. 
The Go4 event classes can be used to construct at runtime complex (composite) events which are stored by Go4 in trees and branches without explicit programming. 
The Go4 GUI includes a browser and tree viewer which can be used without analysis to process standard ROOT files. The tree viewer resolves arbitrary hierarchy levels of composite event trees.


Go4has been developed on Linux  and was tested e.g. in the following environments:

Suse 10.2 (x86_64), SuSe 11.3 (x86_64), SuSe 12.2 (x86_64), SuSe 13.2, OpenSUSE Leap 42.2, OpenSuSe Tumbleweed, Debian 3.1, Debian 4.0 (32 bit and 64bit), Debian 5.0/6.0/7.x/8.1/9.x,  Ubuntu 11.10
with compilers: gcc 3.3.5, gcc 4.1.x, gcc 4.3.2, gcc 4.5.0, gcc 4.6.1, gcc  4.7.x, gcc 4.8.x
It should be portable to other UNIX platforms supported by ROOT.

Since May 08:  Go4runs on Solaris (SunOS 5.2, CC 5.8)
Since November 09:  Go4 with full GUI on Windows XP/ Windows 7
Since May 2010: Go4 on Mac OS X 10.6 with Qt4-X11 (experimental!)
Since November 2013
:  Go4  with web-server as monitoring and control interface (requires DABC framework)

 New since June 2015: Go4 v5 with full control via HTTP server (Go4 GUI or web browser)