This is libxfcegui4, which contains basic GUI related functions and classes used in the Xfce Desktop Environment. NOTES for XFree86 users: ------------------------ If you are running XFree86, it is most likely, that you have only a static variant of libXinerama installed. That might prevent you from using Xinerama with XFce4 at all. So, in order to create a shared variant of -lXinerama, become root and type the following commands: cd /usr/X11R6/lib ld --whole-archive -share -o libXinerama.so.1 libXinerama.a ln -s libXinerama.so.1 libXinerama.so After that you need to rebuild and reinstall the whole XFce4 desktop. If you have any problems with the above, please mail to benny@xfce.org.