Included in the top-level directory of your Tomcat distribution (both binary and source distributions) are some plain text files that contain a wealth of information. They include the text of the Apache Software License that you must agree to to use or redistribute Tomcat, notes about how to install the particular version of Tomcat you have, how to run it, release notes about your version of Tomcat, information about the file structure of your Tomcat version, and the future release plan as it was at the time your version was released. This information is available to you whenever you are not connected to the Internet and can serve as a handy quick reference.

The Apache Tomcat web site (http://tomcat.apache.org) is the official place for Tomcat documentation. On that page is general information about the Tomcat servlet container project, including a link to the documentation for each major release version branch of Tomcat. Click on one of the Tomcat versions, and you'll see HTML documentation that is specific to that major release (6.0, 5.5, or 5.0, for example). The HTML documentation on the Web is generous but tends more toward reference.

The Tomcat developers have also bundled this documentation in the Tomcat distribution as a self-contained web application; in a stock Tomcat installation, you can browse to the file $CATALINA_HOME/webapps/tomcat-docs/index.html. If you have left the docs web application enabled, you can also view this documentation through your own Tomcat instance at http://localhost:8080/docs. The Apache Tomcat web site always hosts the up-to-date version of the docs, but the one in your own Tomcat distribution is specific to the version of Tomcat you have.

There are two Apache Tomcat mailing lists: tomcat-user, for user questions, and tomcat-dev, which is only for Java programmers actively working on Tomcat internals. Please believe that most of the questions that would occur to you in your first few months with Tomcat have already been asked and answered (hundreds of times in most cases), so check the archives first before you post a question to any mailing list.

Links to the Apache Tomcat mailing list archives are listed at http://tomcat.apache.org/lists.html. As of this writing, both the tomcat-user and tomcat-dev mailing list archives are searchable. If you have a question and need an answer, type some or all of the words of your question into the search field, and you will get a list of mailing list messages that may have your answer.

Any technical book eventually becomes outdated, just as this one eventually will. We will also likely find "misteaks" (pun intended) after this book goes to print. You can find O'Reilly's companion web site to this book at http://www.oreilly.com/catalog/9780596101060. This site contains links to buying the book, examples, errata, and more.

Also, both of this book's authors may host some content related to this book. You can find their web pages at http://tomcatbook.darwinsys.com and http://tomcatbook.brittainweb.org.

There are many web sites about Tomcat that are not maintained by Apache Software Foundation members. A quick search on your favorite Internet search engine will yield lots of pages about Tomcat. In some cases, the best documentation on the Web about how to do something with Tomcat is on a third-party web site! We've referenced many throughout this book.

If you search all of those references listed earlier, and still don't find your answer, you may want to ask the question again, using these online resources:

Sometimes mailing lists are a bit slow or not very effective when you need multiple answers that require a two-way conversation. In that situation, you may want to log on to the #tomcat chat channel on the irc.freenode.net IRC server. There are usually several experienced Tomcat users lurking there who may be able to answer your questions.

Please ask questions on this IRC channel only after you have looked for the answer in each of the resources listed above. And, please do not ask questions like "Hi guys, can I ask a Tomcat question?" Just ask your technical question and patiently wait for a response. Don't be surprised if it takes 30 minutes or longer before someone begins to converse with you about your question. The people who answer questions in the #tomcat channel are busy, too (probably working with their own Tomcat installations), and when they finally get a chance to read your question they will try to answer you. Try to word your question with specific version numbers, as well. For instance, instead of asking "My Tomcat just shows me an error, can you tell me what's wrong?" you need to give enough information about your installation for us to guess what might be wrong with it. Whenever you ask a question, at minimum you need to provide:

Without the above information, there is not enough context for someone to help you answer your questions. This applies to everyone. If you ask your question without providing the above information, you probably won't receive an answer.

Any help people decide to give you on IRC is completely voluntary and should not be confused with commercial support. As part of the open source community, we're all expected to help each other a little to fix problems we encounter, in addition to asking for help at times—and then only after we've read the documentation.

You can subscribe to the tomcat-user mailing list and ask questions. Again, only do this if you've exhausted other options. It is a high volume mailing list, so make sure you have enough free hard drive space (tens of megabytes) for incoming mail before you subscribe.

The Apache Tomcat web site's mailing list page is at http://tomcat.apache.org/lists.html. Please do yourself and the world a favor and read the How To Ask Questions the Smart Way page at http://www.catb.org/~esr/faqs/smart-questions.html before sending any messages to the mailing lists.

Do not post to a list that you don't subscribe to. Messages with "please reply directly to me because I don't subscribe to the list" are often taken as an insult to the reader and will generally be ignored.

Subscribe to the tomcat-user mailing list and ask your questions. Again, try to be as specific as you can. Be patient for a response, as it often takes more than a day.

If in the course of using Tomcat you discover a bug that compromises security in a reproducible way, and you can provide a test case containing all of the configuration and other information necessary for the Tomcat committers to reproduce the problem, you may email the [email protected] mailing list. This is a private mailing list that goes only to the Apache Software Foundation members who are involved in keeping Tomcat secure.