newbie: can't start webstorm

johnf@linux-workstation:~/WebStorm-135.621/bin> sh ./webstorm.sh
java version "1.5.0"
gij (GNU libgcj) version 4.8.1 20130909 [gcc-4_8-branch revision 202388]

Copyright (C) 2007 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Exception in thread "main" java.lang.NoClassDefFoundError: javax.swing.UIManager
   at java.lang.Class.initializeClass(libgcj.so.14)
   at javax.swing.UIManager.getUI(libgcj.so.14)
   at javax.swing.text.JTextComponent.updateUI(libgcj.so.14)
   at javax.swing.text.JTextComponent.<init>(libgcj.so.14)
   at javax.swing.JEditorPane.<init>(libgcj.so.14)
   at javax.swing.JTextPane.<init>(libgcj.so.14)
   at com.intellij.idea.Main.showMessage(Main.java:207)
   at com.intellij.idea.Main.showMessage(Main.java:194)
   at com.intellij.idea.Main.main(Main.java:80)