In order to run Gate, you have to to tell your OS where the executable Gate is located. You can add the path to your executable to your PATH variable: export PATH=<your path to Gate>/bin/Linux-g++:$PATH or use the setenv command instead of export. You can then type "Gate" to get it started. /ida <div class="gmail_quote">Den 14 oktober 2009 12.38 skrev Marko T. Oreskovic <<a href="mailto:mtoreskovic@yahoo.com">mtoreskovic@yahoo.com</a>>: <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><table border="0" cellpadding="0" cellspacing="0"><tbody><tr><td style="font-family: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; font-size: inherit; line-height: inherit; font-size-adjust: inherit; font-stretch: inherit;" valign="top"> Hi Ida, Simon I have checked my root/include directory and this is where all .h header files are located (I don't have another root directory inside include directory). My problem was about ROOTSYS environmental variable and scrip I was using to set some other variables, here you can read more: <a href="http://ubuntuforums.org/showthread.php?t=1290178" target="_blank">http://ubuntuforums.org/showthread.php?t=1290178</a> I'm still not sure how I got it working, but it works now . I have then started compilation process, and this is my output at the end Compiling GateUIterminal.cc ... Compiling GateVisAttributesMessenger.cc ... Compiling GateVisManager.cc ... Compiling GateXMLDocument.cc ... source/management finished Creating/replacing object files in ./tmp/Linux-g++/Gate/libGate.a ... ar: creating ./tmp/Linux-g++/Gate/libGate.a Compiling Gate.cc ... In file included from ./source/mandatory_G4_classes/include/GateRunManager.hh:46, аааааааааааааааа from Gate.cc:18: /usr/share/geant4/geant4.9.2.p01/source/run/include/G4RunManager.hh: In member function Сvoid G4RunManager::SetRandomNumberStoreDir(G4String)Т: /usr/share/geant4/geant4.9.2.p01/source/run/include/G4RunManager.hh:352: warning: ignoring return value of Сint system(const char*)Т, declared with attribute warn_unused_result Using granular libraries ... Linking Gate ... ... Done! There were some warn_unused_result warnings, but I'm not sure if this is a serious problem. If this is a successful compilation how do I start Gate, or some examples ? I have tried to type "Gate" and "Gate benchmarkPET.mac" at command prompt but I got "bash: Gate: command not found" regards Marko </td></tr></tbody></table> </blockquote></div>