Java™ Application Development on Linux - Dator

17.2 The IBM SWT Toolkit37917.2.2 Duplicated Effort. Why Cover It?The next logical question is, “If you think SWT is unnecessary with Swing alreadythere, why cover it in your book?” Also a sensible question. The answeris that there is very little published literature on this library (a notable exceptionbeing Chapter 10 of The Java Developer’s Guide to Eclipse by Shaver et al., fromAddison-Wesley). Also, SWT provides the only fully functional GUI librarythat will work with the GNU Compiler for Java. As such, it is a major requiredcomponent if you wish to write native compiled GUI applications on Linuxsystems.Of course, there is another reason. Anyone heavily into Linux is well awareof the political and philosophical debate about Free Software and Open Source.If the core values of Free Software are critical for you, you should be aware thatthe IBM Common Public License 5 under which Eclipse (and thus SWT) arepublished is a Free Software license. You get the source code, you may use itin your own products, and it imposes obligations similar to the GNU GPL, 6but goes even further by requiring you to grant royalty-free licenses for anypatents you hold in derivative works.So you might choose SWT (or not) for political or philosophical reasons.Both authors still suggest Swing first because it is the official Java GUI library.When an employer wants to know if you can write a Java GUI application, heor she almost certainly means a Swing application. Philosophy is great, but itmay not put the food on your table. You need to know that Swing is not FreeSoftware (and neither is either of the major Java SDKs), and SWT is FreeSoftware, but it is up to you to decide what best serves your interests. 75. http://www.eclipse.org/legal/cpl-v10.html6. http://www.gnu.org/licenses/gpl.html7. A lot of people couldn’t care less about the Free versus non-Free issue, but I must say thatmany of my most interesting workplace discussions have arisen from this issue. It is the firstissue in my career that has had programmers talking about the balance between their personalinterests, their employers’ interests, and the public interest. Wherever you stand philosophically,I think it is good that programmers are thinking about the consequences of their work at allof these levels. I wish there were more pressure at all levels of business to consider and balanceall of these interests.