For info, I installed Ubuntu 16.04 and XOP does not run: ------------------------------------------------------ chac:~/tmp % /scisoft/xop2.4/xop /scisoft/xop2.4/xop environment variables: XOP_HOME: /scisoft/xop2.4 XOP_MODE: EMBEDDED XOP_TASK: xop IDL_DIR: /scisoft/xop2.4/idl83 IDL_PATH: DISPLAY: :0 Starting XOP task: xop in EMBEDDED mode. Executing: /scisoft/xop2.4/idl83/bin/idl -em=/scisoft/xop2.4/xop.sav /scisoft/xop2.4/idl83/bin/bin.linux.x86_64/idl: error while loading shared libraries: libXp.so.6: cannot open shared object file: No such file or directory ------------------------------------------------------ Unfortunately libxp.so.6 is not available from the standard repositories: ------------------------------------------------------ chac:~/Downloads % sudo apt-get install libxp Reading package lists... Done Building dependency tree Reading state information... Done N: Ignoring file '50unattended-upgrades.ucf-old' in directory '/etc/apt/apt.conf.d/' as it has an invalid filename extension E: Unable to locate package libxp ------------------------------------------------------ One should install the old debian package: Go to the page: http://www.ubuntuupdates.org/package/core/vivid/main/base/libxp6 and download the "64-bit deb package" Then ------------------------------------------------------ cd ~/Dowloads sudo dpkg -i libxp6_1.0.2-2_amd64.deb ------------------------------------------------------