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A glossary of terms important to IBM mainframe machines
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z misc.
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J2EE: Java 2 Platform, Enterprise Edition. The Java Software Development Kit (SDK), tools, APIs, and the Java runtime (i.e., execution environment) targeted at Java developers building enterprise-class, server-side applications.
JAAS: Java Authentication and Authorization Service. Provides a security model for the Java platform, which permits access to Java-controlled resources based on the identity of the user on whose behalf the Java program is running, rather than the source of the code.
JAD: Joint Application Development/Design. Technique, developed by IBM in the 1970s, for involving users in application development projects. Involves assembling a group of users with a business/systems analyst and locking them up in a room until they all agree on what an application should look like. JAD became fashionable again in the early 1990s as part of RAD.
JANET: Joint Academic NETwork. The WAN which links UK academic and research institutions. The hub is the JANET subnetwork, a private X.25 packet-switched network that interconnects sites, and also links to the Internet.
Java: An object-oriented programming environment developed by Sun towards the end of 1995. Java creates applets which can be downloaded across the Internet, and which will allow clients running, for example, the HotJava browser to interact with objects on the Web and intranet servers. Sun believed that if Java really took off, fat PCs would become a thing of the past; users will simply download software (applets) to Network Computers. Sun makes its Java technology widely available; many vendors, including IBM, have licensed JavaOS and HotJava. And Java is available on many platforms, including IBM’s.
Java 2: Umbrella term introduced by Sun in December 1998 to refer, henceforth, to all subsequent Java initiatives and products.
Java application server: Application server written in Java, and as such platform independent, geared to facilitate the development and deployment of Java-based applications, applets, and servlets – e.g., BEA WebLogic.
JavaBeans: A platform-independent, software component technology for building reusable Java components called Beans. Adopted by IBM, Sun, Netscape and Oracle amongst others. The JavaBeans component model specifies how to build reusable software components, how the resulting Beans describe their properties to visual rapid application development tools and how they communicate with each other. Beans can be combined to create applications or applets.
Java Communications API: Allows AIX Java applications to access RS232 serial ports and IEEE 1284 parallel ports.
Java Jive: Code name for prototype software from IBM and Sun aimed at giving blind people greater access to the Internet by reading aloud the information on a computer screen, along with instructions for using the computer keyboard instead of a mouse. Product name became Home Page Reader. Part of IBM’s Independence Series.
Java Virtual Machine: The facility which allows Java applets/source code to run on a computer. Supported by Web browsers, OS/400 and other platforms.
JBIG: Joint Bilevel Image Group compression. A late addition to image transmission standards, which became an international standard in 1993 (ISO/IEC 11544). The JBIG algorithm is enhanced for bitonal compression such as with text and line drawings.
JBOD: Just a Bunch Of Disks. A RAID system which doesn’t try to be too clever, and thus avoids the problem of getting into quasi-theological arguments about whether it’s RAID 0, 1, 5, or 42, how many angels you can get on its HDA, etc.
JCE: Java Cryptography Extension. AIX1 software that provides a framework and implementations for encryption, key generation and key agreement, and MAC1 algorithms. Support for encryption includes symmetric, asymmetric, block and stream ciphers. Also supports secure streams and sealed objects.
jCentral: A tool for Java developers that acts as both a search engine and a repository for Java resources. It collects, combines and organizes Java information including applets, JavaBeans, source code, white papers and FAQs. It also allows developers to query this information by resource type.
JCICS: Java CICS classes. A Java Class library that provides direct access to CICS resources. Used in object-oriented programming, replacing the CICS Foundation Classes.
JCL: Job Control Language. The language used to describe the steps of a batch job (files to be used, programs to be run, etc). A generic term, hijacked by IBM to refer to the batch control languages for its System/360 operating systems. Then, as now, z/OS and VSE/ESA JCL is a clumsy and cumbersome system that is hard to learn, full of inconsistencies, and avoided by anyone with an iota of common sense and access to an alternative. The only excuse for it comes from one of the original OS/360 developers: they ran out of time to build a JCL interpreter, so just used the Assembler macro processor, and built a language (JCL) around it.
JDBC: Java DataBase Connectivity. An API that is designed for use by Java database applications, and has the same characteristics as Open Database Connectivity (ODBC). JDBC was primarily developed by Sun Microsystems and provides a clean, simple way for Java code to access relational databases and other persistent data resources.
JDK: Java Development Kit. Software development kit from Sun consisting of a Java compiler, a debugger, standard Java classes, and a Java runtime (i.e., JVM) for Unix. Replaced, in Java 2, by Java Platform, sometimes referred to as the Java SDK.
JECL: Job Entry Control Language. The equivalent of JCL for z/OS and VSE/ESA batch processing subsystems: JES2, JES3, POWER1. No longer commonly used for JESx; JES3 Control Statements is used instead.
JES2: Job Entry Subsystem 2. One of two batch processing subsystems available for z/OS, both developed in the 1960s, and each with a different heritage, and different control statements (JECL). JES2 was originally HASP. Each reads batch jobs in, schedules their execution and spools their output. JES2 is, by far, the most popular, but JES3 is used in a much smaller number of very large organizations. An element of z/OS.
JES3: Job Entry Subsystem 3. One of two batch processing subsystems available for z/OS, both developed in the 1960s, and each with a different heritage, and different control statements (JECL). Each reads batch jobs in, schedules their execution and spools their output. JES2 is, by far, the most popular, but JES3 is used in a much smaller number of very large organizations. JES3 usage declined markedly during the 1990s as corporations merged their data centers as part of rationalizing an acquisition of another corporation. Although there were exceptions, JES2 tended to win if each data center used a different JESx. JES3 is an optional, separately priced feature of z/OS.
Jini: Described as a connection technology from Sun, Jini (which also does not stand for anything) is simply a way of plugging devices into a network and having them work right away, without any setups.
JISC: Japanese Industrial Standards Committee.
JIT: Just In Time. An inventory minimization approach developed in the Manufacturing sector. It focuses on both inventory from suppliers (input) and inventory from the manufacturing process (output). Suppliers must deliver goods just before they are needed. And products must be manufactured at just about the same time that they are ordered by customers.
JNDI: Java Naming and Directory Interface is a standard extension to the Java platform, which provides a unified interface to multiple naming and directory services.
Jodax: A high-level Java library to IBM’s DB2 database.
JPEG: Joint Photographic Expert Group. A standard for defining and compressing raster (bit-mapped) images. And the name of the committee, created by two international standards bodies, that developed the JPEG standard. Very popular, especially on the Web.
JPEG2000: A standard intended to replace the original JPEG image compression technique, from the same committee. JPEG2000 is based on wavelet compression algorithms which allow images to be broken down and compressed in a more flexible manner than standard JPEG. The standard allows the user to choose parts of an image to download, view, and enlarge without losing resolution. The standard also allows images to be encrypted.
JSP: JavaServer Pages. Uses XML-like tags and scriptlets to encapsulate logic that fills out the dynamic content of HTML pages. An extension of the servlet technology, JSP is the Java analog of Microsoft’s ASP5.
JSSE: Java Secure Sockets Extension. Enables secure Internet communications and implements a Java version of SSL and TLS protocols in AIX1. JSSE includes functionality for data encryption, server authentication, message integrity and client authentication.
JTA: Java Transaction Application Programming Interface. Specifies standard Java interfaces (API) between a transaction manager and the parties involved in a distributed transaction system: the resource manager, the application server, and the transactional applications.
JTAG: Joint Test Action Group. The IEEE 1149.1 boundary-scan standard, named after the group that developed it. It solves test access problems introduced by advanced IC4 packages. Used to test the interconnection between SRAM I/Os and printed circuit board traces or other components.
JTS: Java Transaction Service. Specifies the implementation of a Transaction Manager which supports JTA at the high level and implements the Java mapping of the OMG Object Transaction Service (OTS) specification at the low level. JTS uses the standard CORBA ORB/TS interfaces and IIOP for transaction context propagation between JTS Transaction Managers.
Jumbo frames: Optional enhancement to Fast/Gigabit Ethernet adapters (e.g., IBM OSA-Express adapter) to permit 9,000 byte frames, six times the standard frame size, to be transmitted to expedite data transfers.
Jupiter: An unannounced storage architecture designed to work with Summit. Eventually most of the data management products would run on Jupiter hardware, thus freeing up the Summit for more application processing. Also known as Olé. Jupiter was also used as an early code name for the original SMS1 project. Little is heard of the notion today.