************************************* * * * DB/C Newsletter * * April 2002 * * * ************************************* News and Comments DB/C JX is now free! Technical details about how we have made DB/C JX an open source project are detailed in this month's newsletter. The reason for this change is that DB/C JX has not been as successful as we had hoped. Without sufficient revenue, we can no longer afford to support and enhance DB/C JX. Instead of just shelving it, we decided to make it open source. This will allow individuals and organizations to use DB/C JX with confidence that they can fix any problems that arise. The initial open source release is JX Release 3.0. Note that we've dropped the 'DB/C' from its name. JX 3 is written in Java. Unlike DB/C JX 2, JX Release 3.0 requires DB/C FS to use traditional DATABUS file I/O. However, in the spirit of the open source movement, I expect someone will take up the task of writing a single user DATABUS file system package that can be plugged into the JX 3 runtime so that the requirement for using DB/C FS will disappear. DB/C Software Company will initially support the JX 3 open source project in these ways: 1. provide the host web server for the source and object files 2. provide email lists for JX users and developers 3. provide the project maintenance function for integration of changes The use, distribution and modification of JX 3 software is governed by the JX 3 User License Agreement. This agreement essentially allows for any use of the source, object and documentation without payment of license fees or royalties. In addition, the license does not impose any requirements with regard to distribution of derivative works. Thus, unlike the Gnu General Public License (GPL), if you incorporate parts of JX 3 into your software, you do not have have to contribute your software or changes to JX 3 back to the public domain, and you can charge money for your software. All of the information about JX 3 and how to download it is found at the JX home page which is accessed via the DB/C JX link at www.dbcsoftware.com. Existing users of DB/C JX 2 will continue to receive support from DB/C Software Company until the term of their current support subscription expires. don.wills@dbcsoftware.com ****************************************************************************** JX is Free! JX Release 3.0 consists of Java source files, object files (.jar files), basic documentation in the form of the HTML files, and the jxreadme.txt file. To use JX 3, you will need to download the object files, documentation, and jxreadme.txt files. You do not need to download the JX 3 source files if all you want to do is use JX 3. The JX object files are jxcmp.jar and jxrun.jar. The JX compiler consists of the classes of the com.dbcswc.jxcmp package that are contained in jxcmp.jar. The JX runtime support package consists of the classes of the com.dbcswc.jxrun package that are contained in jxrun.jar. The JX compiler compiles DB/C source programs into Java .class files. These .class files may be run by a Java Virtual Machine, just like .class files created by a Java compiler. The classes contained in the jxrun.jar file must be available at runtime for the .class files created by the JX compiler. JX 3 differs from DB/C JX 2 in one fundamental way - the compiler and runtime classes are 100% Java. All of the native code that implemented local file I/O and native KEYIN/DISPLAY has been removed from JX 3. Thus, if your programs use traditional DATABUS file IO (OPEN, READ, READKS, etc.), you will need to purchase and use DB/C FS to implement the file IO verbs in your programs. In DB/C JX 2, KEYIN/DISPLAY was implemented in two ways: 100% Java and native library calls. In Windows, the native library calls were implemented via the Win32 console API (more well known as the MS-DOS box). In UNIX, the native implementation was via curses and termdef. None of these native interfaces exist in JX 3. In JX 3, KEYIN/DISPLAY is implemented with the Swing GUI toolkit. The CONSOLE verb can be used with JX 3 to implement simple output for programs that only need to display output to stdout. The HTML documentation contains information about how to compile and run with JX 3. The documentation consists of several HTML files. The index.html file is the place to start. It contains links to the other HTML files that make up the documentation. The jxreadme.txt file contains the latest information about the current release including a list of bugs fixed and the features that have been added recently. The jxtalk email list is where all user-oriented communication about JX 3 will occur. It is a collaborative list where anyone can post messages about JX. See the JX home page to learn how to subscribe to jxtalk. The JX 3 source is stored in a CVS repository at dbcsoftware.com. To get access to the source, you need to use a CVS client to connect with the CVS server running on the dbcsoftware.com server. Login with the user id 'anonymous' without a password using the pserver protocol. The JX 3 CVS repository is in the /home/jxproject directory. The jxdev email list is a separate email list for programmers who are working with the source of JX 3. This includes people who are fixing bugs, or who are enhancing the source by adding new features, or who are using the JX 3 source for other purposes. The repository update function will be done by the JX project maintainer. Initially, the maintainer will be an employee of DB/C Software Company. All changes to program source files and documentation files will be controlled by the maintainer. To submit changes to the maintainer, attach the updated and new files to an email sent to the jxdev email list. The maintainer will review the changes and then either commit them or communicate with the contributor about why the changes were not committed to the repository. The success of the JX open source project will be directly related to the involvement of users and developers. If you are interested in using a free, open-source DB/C language development environment, you should become active in this project. ****************************************************************************** DB/C Language Class Schedule Class: DB/C Programming Language Fundamentals Date: June 2002 Location: Oak Brook, Illinois For information, send email to admin@dbcsoftware.com. ****************************************************************************** Subscribing to the DB/C Newsletter If you don't already have the DB/C Newsletter delivered to your email address and would like to have it emailed to you monthly, just send an email message to 'dbcnews-subscribe@dbcsoftware.com'. The newsletter will be delivered to the email address from which the message was sent.