#!wml --include=..#include "include/layout.wml"#### Special Tags### <faq-section name="XYZ>#	<faq question="ABC">answer</faq>#	<faq question="ABC">answer</faq># </faq-section>	## the section counter#<set-var __SECCNT=1><define-tag faq-section endtag=required>	<preserve name>	<set-var %attributes>{#FAQINDEX#:		<boxtitle><get-var __SECCNT>. <get-var name></boxtitle>		<boxitem>:#FAQINDEX#}	<boxtitle><get-var __SECCNT>. <get-var name></boxtitle>	<set-var __FAQCNT=1>	<boxitem>%body</boxitem>{#FAQINDEX#:		<br>		</boxitem>:#FAQINDEX#}	<increment __SECCNT>	<restore name></define-tag><define-tag faq endtag=required><preserve question><set-var %attributes>{#FAQINDEX#:	<strong><a href="faq/faq.html#faq<get-var __SECCNT>_<get-var __FAQCNT>"><get-var __SECCNT>.<get-var __FAQCNT> <get-var question></a></strong><br>:#FAQINDEX#}	<h3><a name="faq<get-var __SECCNT>_<get-var __FAQCNT>"><get-var __SECCNT>.<get-var __FAQCNT> <get-var question></a></h3>	%body	<br><increment __FAQCNT><restore question></define-tag><set-var last-modified-author="prk"><subject "GNU Classpath FAQ"><box>{#FAQINDEX#}<faq-section name="introduction"><faq question="What is GNU Classpath?"><p>GNU Classpath is a set of essential libraries for supportingthe Java programming language.</p><p>Classpath serves the same role that <ahref="http://www.gnu.org/software/libc/libc.html">libc</a> has for C,but is much richer in functionality. The broadness of the standardlibrary is an important reason why Java has been so successful. Forexample, the library includes frameworks to convert between characterencodings, for accessing relational databases, for building GraphicalUser Interfaces, for encryption, for logging, and for numerous othertasks that are needed to build complex applications.</p></faq><faq question="Why Java?"><p>On the GNU operating system, we want to run software independent ofthe programming language in which it was written. Because Java iswidespread, and because Java has some nice features, we want tosupport Java as well.</p></faq><faq question="But isn't Java free already?"><p>Sun Microsystems, the company who has created Java, currentlydistributes the &#x201c;Java Development Kit&#x201d; and &#x201c;JavaRuntime Environment&#x201d; at no cost. The former even comes with thesource code of the standard class library. However, the &#x201c;SunCommunity Source License&#x201d; <ahref="http://www.gnu.org/licenses/license-list.html#SunCommunitySourceLicense">doesnot grant essential freedoms</a>, for example the right to distributea modified version of the code.</p><p>Therefore, Sun&#x2019;s implementation does not qualify as FreeSoftware.</p></faq><faq question="What do we need to make Java free?"><p>Though it would be helpful if Sun would open their sources, this is not themost important step toward a free Java. Even more important for a free Java are:<ul><li>Access to the TCK (Technology Compatibility Kits) on acceptable terms<li>Involvement in the JCP without contamination or other unacceptable   constraints<li>Easing of the requirements on subsetting.  The free software   community doesn't work well with the "one big perfect release"   model that Sun seems to want.  </ul><p>There was already a lot of discussions around this topic on other sites:<ul><li><createlink name="Sys-Con: <i>Let's Bundle Free Java with Linux</i>, Says IBM's Sutor" url="http://sys-con.com/story/print.cfm?storyid=43969"><li><createlink name="Hacking Log 4.0: RE: JCP 2.6 - Are we there yet?" url="http://linuxintegrators.com/blog/acoliver/news/?permalink=0124.html"><li><createlink name="Javalobby: ESR - Open Letter to Sun: Let Java Go" url="http://www.javalobby.org/thread.jspa?forumID=61&threadID=11412"></ul></faq><faq question="Is GNU Classpath all that is needed for running Java programs?"><p>GNU Classpath is a free implementation of Java&#x2019;s standardlibrary.  To execute Java programs, it is also necessary to have aJava Virtual Machine (JVM). This component manages memory, enforcessecurity restrictions, compiles Java bytecodes to the instruction setof your computer, and provides other runtime services.  There existseveral projects for <createlink name="free JVMs" url="stories.html#jvm">. Most use GNU Classpath as theup-stream source for their library.</p><p>Java programs can also be compiled &#x201c;ahead of time,&#x201d;like C++ or other compiled languages. The GNU Compiler Collection(GCC) does this, and its Java library is mostly derived from GNUClasspath.</p></faq></faq-section><faq-section name="licensing"><faq question="Under which licence is GNU Classpath released?">GNU Classpath is licensed under the GPL plus a special exception:<blockquote><p><code>Linking this library statically or dynamically with other modules ismaking a combined work based on this library.  Thus, the terms andconditions of the GNU General Public License cover the wholecombination.</code></p><p><code>As a special exception, the copyright holders of this library give youpermission to link this library with independent modules to produce anexecutable, regardless of the license terms of these independentmodules, and to copy and distribute the resulting executable underterms of your choice, provided that you also meet, for each linkedindependent module, the terms and conditions of the license of thatmodule.  An independent module is a module which is not derived fromor based on this library.  If you modify this library, you may extendthis exception to your version of the library, but you are notobligated to do so.  If you do not wish to do so, delete thisexception statement from your version.</code></p></blockquote></faq><faq question="Where can I find more about the GPL?">Please check the FSF FAQ on the GNU GPL: <createlink name="http://www.fsf.org/licenses/gpl-faq.html" url="http://www.fsf.org/licenses/gpl-faq.html">.</faq><faq question="What does the exception allow me to do?"><p>If you combine GNU Classpath <em>with independent modules to produce anexecutable</em> you can <em>copy and distribute the resulting executable underterms of your choice</em>.</p><p>So you can use and distribute GNU Classpath as is in your program without changing the license of your software.</p></faq><faq question="I have a question about licensing GNU Classpath. Who can I ask?">Direct such questions to <a href="mailto:licensing@gnu.org">licensing@gnu.org</a>. The FSF is theofficial copyright holder of Classpath and sets the distribution terms</faq><faq question="How can I be sure that my application does not break the license?">The FSF has a GPL-compliance lab which offers consulting services forcompanies who are working to develop products that incorporate FreeSoftware so that they can do so in ways that comply with the terms ofthe GPL and other Free Software licenses. If you are interested in thisservice, please write to <a href="mailto:compliance-lab@fsf.org">compliance-lab@fsf.org</a>.</faq></faq-section><faq-section name="Classpath Development"><faq question="I would like to contribute, where shall I start?"><p>See the <ahref="docs/">documentation page</a>, especially the <ahref="docs/hacking.html">GNUClasspath Hacker&#x2019;s Guide</a>, and pick up a <createlink name="task" url="tasks.html"> from the list!</faq><faq question="Can I look at source code distributed with otherimplementations to get inspiration?">If you are going to contribute source code to GNU Classpath we mustmake sure that you have not studied the source code of the JDK/JRE ordecompiled any of its classes. Furthermore you must not have signedany non-disclosure agreements with Sun or other companies in regardwith java technology that might cover the core class libaries ortools. The reason for this requirement is that we want to make surethat Sun or any other company cannot rightfully claim that GNUClasspath infringes their copyright. You are therefore questionedabout your experience with other implementations of similar sourcecode and any agreements with companies you might have signed when yourequest to contribute to GNU Classpath.<p>Please note that this does not mean you cannot help GNU Classpath atall in such a case. Here is a list of things you can do instead:<ul>  <li>write Mauve test cases</li>  <li>write example applications demonstrating the usage of the packages</li>  <li>writing/fixing helper programs (like japitools) and scripts</li>  <li>report bugs</li>  <li>help fixing the documentation</li>  <li>help in other related Free software projects  (e.g. virtual machine development,   <createlink name="GUMP" url="http://gump.apache.org/">)</ul><p>Here are some rough guidelines for deciding whether or not it would bewise to accept a contribution from someone that studied source codefor another implementation of the core libraries or is under contractwith some company covering implementations of core library classes.<p>If the developer got access to the source code by signing somecontract (like the SCSL) with Sun then it would be best to examinethat contract (by FSF legal) before deciding.<p>If the developer just accidentally saw some of the source code and hadno intention (and didn't actually) study the implementation (with theintention of contributing to GNU Classpath) there is no problem.<p>Studying a proprietary implementation with the intention ofimplementing it (better) for GNU Classpath is a clear no-no.<strong>The general rule is that if you have looked at or studied any(proprietary) implementation of a package you should not work on thatpackage for GNU Classpath.</strong> That is because it would bedifficult to proof that you really did an independentimplementation. Since what you create might look very similar (whichis not unlikely). Working on something completely unrelated is OK (aslong as there are no contractual obligations with Sun or some othercompany to not do this of course).<p>The important thing is that we want to be clear on the fact that wecreated an independent implementation. We don't want to get intotricky legal situations. We want to avoid risking to go to court overreverse engineering or clean room situation questions if notabsolutely necessary. That is why we in general just say "please don'tcontribute if you looked at other implementations". If someone thinksthat their actions might be explained as copying directly orindirectly another (proprietary) implementation then that could be aproblem that we want to avoid.<p>FSF Legal will always advise not to take any unnecessary risks thatmight endanger the (perceived) free software status of a GNUproject. (If we might need to go to court to proof that what we didwas OK, then don't!)<p>This isn't a GNU Classpath project specific issue.See <createlink name="GNU: Reading Non-Free Code"url="http://www.gnu.org/prep/standards/html_node/Reading-Non_002dFree-Code.html">.</faq><faq question="I'm tainted by; can I help anyway?">Even if you have seen Sun's source and you cannot contribute code to GNU Classpath, there are still many way you can help us.Here's a few examples of contributions you can make that would greatly help us:<ul><li>Mauve test cases<li>Example programs for GNU Classpath<li>Documentation fixes<li>Help programs (e.g. japitools) and scripts</ul>In general, if you just accidentally saw some of the source code and had no intention (and didn't actually) study the implementation (with the intention of contributing to GNU Classpath), there is no problem.In case of doubt, please refer to FSF legal.</faq><faq question="Why do I have to give the copyright to the FSF?">Some contributors of Classpath might be annoyed if their work was beingused under conditions that are not according to the terms of the license.However, enforcing the license in court (if this was ever needed) wouldbe easier if the Free Software Foundation can claim to speak in the nameof all authors. For this reason, and for others that are specific to theintellectual property system of the United States, GNU projects tend tobe a bit picky about getting signatures from all contributors. Please donot see this as a personal offence.