1 IcedTea

        2 =======

        3 

        4 The IcedTea project provides a harness to build the source code from

        5 openjdk.java.net using Free Software tools and dependencies.

        6 

        7 IcedTea addresses two problems: it eliminates the build requirement on

        8 proprietary build tools and it provides replacements for the

        9 "encumbered binary plugs".

       10 

       11 These plugs are described at http://openjdk.java.net: "Not all of the

       12 source code that makes up the JDK is available under an open-source

       13 license. In order to build an OpenJDK binary from source code, you

       14 must first download and install one or more of the following files

       15 from which the build process will copy over 'binary plugs' for these

       16 encumbered components."

       17 

       18 This project uses code from GNU Classpath, code generated during a

       19 build of the openjdk.java.net source code, and stub code written by

       20 Red Hat, to provide Free Software replacements for these encumbered

       21 binary plugs.

       22 

       23 IcedTea also provides build scripts and patches that allow the source

       24 code from openjdk.java.net to be built with ecj running on libgcj or

       25 with IcedTea itself.

       26 

       27 See INSTALL for build instructions.

       28 

       29 Homepage (wiki):

       30   http://icedtea.classpath.org/

       31 

       32 Bugs (bugzilla):

       33   http://icedtea.classpath.org/bugzilla

       34 

       35 Mailing List: 

       36   distro-pkg-dev@openjdk.java.net

       37   http://mail.openjdk.java.net/mailman/listinfo/distro-pkg-dev

       38 

       39 FAQ:

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

       41 

       42 Anonymous Mercurial checkout:

       43   hg clone http://icedtea.classpath.org/hg/icedtea

       44 

       45 Java compatibility

       46 ------------------

       47 

       48 IcedTea is derived from OpenJDK, Sun's open-source implementation of

       49 the Java SE platform.  At this time the build from which IcedTea was

       50 constructed corresponds to an early build (b21) of JDK 7.  When JDK 7

       51 is complete it will implement the Java SE 7 Platform Specification.

       52 Work on that specification is underway, but far from final.  Any APIs

       53 in the JDK 7 implementation, whether new or old, are therefore subject

       54 to minor adjustments, major revisions, or even outright removal

       55 between now and the time that the Java SE 7 Platform Specification is

       56 finalized.  Please take these facts into account before depending upon

       57 IcedTea.

       58 

       59 How the Stub Replacements were Produced

       60 ---------------------------------------

       61 

       62 To produce the plug replacements, we began by satisfying as many

       63 undefined references as possible using code from a completed build of

       64 the source code from openjdk.java.net.  Then we supplemented the

       65 resultant tree with more replacement code from GNU Classpath.

       66 Following that, we fixed each remaining build error by creating the

       67 simplest possible stub code.

       68 

       69 A Note About License Headers

       70 ----------------------------

       71 

       72 Some sources downloaded from openjdk.java.net do not display the GPL

       73 license header.  Instances are:

       74 

       75  - The files in openjdk/j2se/src/share/classes/javax/xml/stream/ seem to 

       76    comprise the BEA-StAX source code

       77 

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

       79 

       80    with some Sun-specific modifications.  We're assuming that Sun is

       81    bundling BEA-StAX under the terms of the Apache License 2.0 and

       82    that the modifications are owned by Sun.

       83 

       84  - We are assuming that these files are owned by Sun:

       85    openjdk/j2se/src/share/classes/**/resources/*.properties

       86 

       87 The downloaded sources include a script that inserts proprietary

       88 license headers into the source files it generates.  The script

       89 itself is GPL'd so we patched them to emit the GPL header. The

       90 file is:

       91   openjdk/j2se/make/java/nio/genExceptions.sh

       92 

       93 

       94 gcjwebplugin

       95 ============

       96 

       97 gcjwebplugin provides basic support for running applets in

       98 Mozilla-based web browsers.  It does not support applet/Javascript

       99 communication (LiveConnect) and support for signed applets needs

      100 further testing.  The current applet security manager may be too

      101 strict and may require tuning to allow otherwise-legitimate calls by

      102 untrusted applets.

      103 

      104 gcjwebplugin itself is a shared object, gcjwebplugin.so, built from a

      105 single source file, gcjwebplugin.cc.  The IcedTea adaptation of

      106 gcjwebplugin communicates through named pipes with a modified version

      107 of IcedTea's appletviewer.  Two source files,

      108 openjdk/j2se/src/share/classes/sun/applet/PluginAppletViewer.java,

      109 openjdk/j2se/src/share/classes/sun/applet/PluginMain.java are added to

      110 rt.jar and tools.jar to provide gcjwebplugin with an interface into

      111 the appletviewer code.  This support code is provided in

      112 patches/icedtea-plugin.patch.