Weka running for Linux and Unix

(1) Under package weka.gui

LookAndFeel.props

(2) uncomment the first configuration

# Look'n'Feel configuration file
# $Revision: 1.1.2.2 $

# the theme to use, none specified or empty means the system default one
Theme=javax.swing.plaf.metal.MetalLookAndFeel
#Theme=com.sun.java.swing.plaf.gtk.GTKLookAndFeel
#Theme=com.sun.java.swing.plaf.motif.MotifLookAndFeel
#Theme=com.sun.java.swing.plaf.windows.WindowsLookAndFeel
#Theme=com.sun.java.swing.plaf.windows.WindowsClassicLookAndFeel