Welcome to the wonderful world of copyrights and licenses. All the utilities and code developed in this book are open source. Their copyrights are owned by the good people at Addison-Wesley, but you can use the utilities and code under the terms of the GNU General Public License ( GPL ), Version 2, included as Appendix A. This is the same license under which Linus Torvalds makes the Linux operating system available. I hope you and your organization will feel comfortable using this stuff without having to get the lawyers involved.
In the final analysis the terms of the GPL take precedence, but here is what I intend.
You may use the executable, binary forms of the utilities in any way you wish for any purpose, whether it is public, private, commercial, not-for-profit, and so on.
If you use the binaries, you do so with the understanding that no warranty of any kind is offered by anyone . The only exception is the case where you have explicitly executed a contract for warranty support with someone. (Just so the lawyers and my editor at Addison-Wesley don't have anything to worry about, let me make it very clear that your purchase of this book doesn't imply such a warranty contract. If it did, the book would be a lot more expensive. However, we thank you for buying it anyway!)
You may freely distribute the source code and binaries in their original form, provided that they are accompanied by the GPL and that you give appropriate notice of the Addison-Wesley copyright as well as a disclaimer of warranty. As is the case with Linux, you may charge a reasonable fee for your copy or distribution costs. You may offer warranty support for a fee.
You may modify or use parts of the source code in your programs so long as you retain the existing copyright notices and make your modifications available under the GPL.
The synopsis above applies to everyone. Here are my intentions for more specific groups of readers and users.
If you are a consultant, you may make the binaries available to your clients for a nominal fee to cover actual copy costs. You may modify the source code and offer the resulting binaries to your customers, again for only a nominal copy fee, so long as you observe the GPL and make those modifications freely available to others (like me!) under the terms of the GPL. You may accept payment from your clients for performing the modifications, but you need to make sure they understand that they don't own the modified code. You may contract with your clients to offer warranty support.
If you are a vendor of proprietary business applications software that does not natively support XML, you may make the binaries available to your customers for a nominal fee to cover copy or distribution costs. If you want to build native XML import/export support into your business application, you may use the algorithms and DOM processing techniques in your proprietary product, but you may not use the source code in your product.
If you are a vendor of proprietary EAI, EDI translation and management, or other middleware software, you may use the contents of this book as an aid to your development efforts. You may use the more common and generic techniques and algorithms. You may not use either the unique design approaches or the source code.
In short, I hope that you benefit indirectly from the programs and the source code and that you feel free to share them with others. However, don't look to me for free warranty support, and don't try to make money directly from this work.
(Oh, and just to make sure I haven't forgotten anything: Everything I just said applies to the binaries and the source code but not to the book itself. It, too, is copyrighted by Addison-Wesley, but we want everyone to pay for copies. We have to get something out of this!)