IcedTea
=======

The IcedTea project provides a harness to build the source code from
openjdk.java.net using Free Software tools and dependencies.

IcedTea addresses two problems: it eliminates the build requirement on
proprietary build tools and it provides replacements for the
"encumbered binary plugs".

These plugs are described at http://openjdk.java.net: "Not all of the
source code that makes up the JDK is available under an open-source
license. In order to build an OpenJDK binary from source code, you
must first download and install one or more of the following files
from which the build process will copy over 'binary plugs' for these
encumbered components."

This project uses code from GNU Classpath, code generated during a
build of the openjdk.java.net source code, and stub code written by
Red Hat, to provide Free Software replacements for these encumbered
binary plugs.

IcedTea also provides build scripts and patches that allow the source
code from openjdk.java.net to be built with ecj running on libgcj or
with IcedTea itself.

See INSTALL for build instructions.

Homepage (wiki):
  http://icedtea.classpath.org/

Bugs (bugzilla):
  http://icedtea.classpath.org/bugzilla

Mailing List: 
  distro-pkg-dev@openjdk.java.net
  http://mail.openjdk.java.net/mailman/listinfo/distro-pkg-dev

FAQ:
  http://icedtea.classpath.org/wiki/FrequentlyAskedQuestions

Anonymous Mercurial checkout:
  hg clone http://icedtea.classpath.org/hg/icedtea


How the Stub Replacements were Produced
---------------------------------------

To produce the plug replacements, we began by satisfying as many
undefined references as possible using code from a completed build of
the source code from openjdk.java.net.  Then we supplemented the
resultant tree with more replacement code from GNU Classpath.
Following that, we fixed each remaining build error by creating the
simplest possible stub code.

A Note About License Headers
----------------------------

Some sources downloaded from openjdk.java.net do not display the GPL
license header.  Instances are:

 - The files in openjdk/j2se/src/share/classes/javax/xml/stream/ seem to 
   comprise the BEA-StAX source code

   http://ftpna2.bea.com/pub/downloads/jsr173.jar

   with some Sun-specific modifications.  We're assuming that Sun is
   bundling BEA-StAX under the terms of the Apache License 2.0 and
   that the modifications are owned by Sun.

 - We are assuming that these files are owned by Sun:
   openjdk/j2se/src/share/classes/**/resources/*.properties

The downloaded sources include two scripts that insert proprietary
license headers into the source files they generate.  The scripts
themselves are GPL'd so we patched them to emit the GPL header.  These
files are:

  openjdk/j2se/make/java/nio/genExceptions.sh
  openjdk/hotspot/src/share/vm/prims/jvmtiLib.xsl


gcjwebplugin
============

gcjwebplugin provides basic support for running applets in
Mozilla-based web browsers.  It does not support applet/Javascript
communication (LiveConnect) and support for signed applets needs
further testing.  The current applet security manager may be too
strict and may require tuning to allow otherwise-legitimate calls by
untrusted applets.

gcjwebplugin itself is a shared object, gcjwebplugin.so, built from a
single source file, gcjwebplugin.cc.  The IcedTea adaptation of
gcjwebplugin communicates through named pipes with a modified version
of IcedTea's appletviewer.  Two source files,
openjdk/j2se/src/share/classes/sun/applet/PluginAppletViewer.java,
openjdk/j2se/src/share/classes/sun/applet/PluginMain.java are added to
rt.jar and tools.jar to provide gcjwebplugin with an interface into
the appletviewer code.  This support code is provided in
patches/icedtea-plugin.patch.
