gcjwebplugin:
a plugin for the execution of Java™ applets in web browsers
WARNING:
The current version does not provide a security manager capable of handling Java (tm) applets. Applets have UNRESTRICTED access to your computer. This means they can do anything you can do, like deleting all your important data.
FAQ

Your build breaks with an error message mentioning libtool

The error message looks as follows:

  libtool: link: unable to infer tagged configuration
  libtool: link: specify a tag with `--tag'
  

This is the infamous libtool 1.5.x bug. Update to gcjwebplugin 0.3.0 or newer. It contains a workaround for this bug.

Copyright (c) 2003, 2004 design and implementation gcjwebplugin team.