Java
Java started out in 1990 as a project headed by James Gosling at Sun Microsystems called Oak. Java is a medium-low level programming language similar to C/C++ but more reliable because of its Oak-origin. Java is "author once, use often", i.e. it is cross-platform since it can be run on any machine that has a Java Virtual Machine or Java enabled browser, eg Netscape Navigator, or a virtual machine or a Java interpreter such as JIT or HotJava.

According to the Sun Microsystems, Java is "a simple, robust, object-oriented, platform-independent multi-threaded, dynamic general-purpose programming environment. It's best for creating applets and applications for the Internet, intranets and any other complex, distributed network." It is a distributed, interpreted, secure, architecture-neutral, portable, and high-performance language.
The best tools for Java development include Symantec's Visual Cafe, Powersoft's NetImpact Studio, Sun's Java Workshop, and Microsoft's Visual J++

Right now Java is competing with Windows CE for the embedded OS market.
Java Server Pages
See JSP.
JavaBean
A Sun Microsystems specification that defines how Java objects interact, especially Java component software. It is also the name for the objects that conform to this specification. JavaBean technology is analogous to Microsoft's ActiveX technology.

Interestingly, JavaBeans can only be developed using Java, but can run on any platform; in contrast, ActiveX can be developed using any programming language but can run only on a Windows platform!
JavaScript
.js. A scripting programming language developed by Netscape Communications as Livescript 1.0. JavaScript and Microsoft's JScript are tied together by ECMAScript, the vendor-neutral version. It is frequently used directly on web pages to provide more features and even execute small programs. It doesn't have to be compiled but can be included directly into an HTML web page and can be interpreted by a JavaScript interpreter like a web browser. This also implies that JavaScript is dynamically bound instead of statically bound like Java, i.e. when a program makes references to other objects, the existence of those objects is checked at compilation for Java but for JavaScript the check is only done at execution. See script.
JavaScript Object Notation
See JSON.
JBOD
Just a Bunch Of Disks Refers to a group of hard disks that are not RAID configured.
JDBC
Java Database Connectivity. Sun Microsystems's protocol that allows Java programs to connect and access any database that is SQL compliant. Since most database management systems (DBMSs) are SQL compliant, and since Java runs on most platforms, Java and JDBC allows the possibility to create a program that can run on different platforms and interact with different DBMSs. See also ODBC.
JDK
Java Development Kit. Sun Microsystems's software development kit (SDK) used to produce Java programs. The JDK supports JavaBeans software components and JDBC.
JET
Joint Engine Technology. The database engine behind Microsoft Access.
JFIF
.jfif. JPEG File Interchange Format. A standard format for exchanging JPEG file between computers.
Jini
(pronounced gee-nee.) Sun software that allows devices to dynamically and interactively connect together. A device attaching to a network via Jini would announce itself, explain its capabilities, and then would be immediately accessible to other devices on the network as well as having access to other devices on the network. Jini allows a network wide sharing of  resources, storage, memory, and processing power.

Jini works by passing applets (little programs) back and forth among devices that can run Java.
JK
Just Kidding.
job object
See process.
join
To relate datasheets of information in a database. Two related tables will have a common column (field) that is the key to the relationship.
• Inner joins (aka equi-joins) bring together rows from two tables   whose common field match.
• Outer joins also include unmatched rows.
• Left joins include all the rows from the first/left table.
• Right joins include all the rows from the second/right table. See also relationships.
Joint Engine Technology
See JET.
Joint Photographic Experts Group
See JPEG.
JPEG
.jpeg or .jpg. Joint Photographic Experts Group. (Often pronounced "jay-peg".) A graphic file format established by photographers. It does lossy compression (roughly 25:1) of graphic intensive files. It has 24 bit color. A format common on the WWW.
JPG
See JPEG.
JPEG File Interchange Format
See JFIF.
JSON
JavaScript Object Notation. A light-weight, human-readable data exchange format that is also the way that JavaScript creates literal objects.

JSON RFC: 4627. JSON MIME: application/json. JSON basic data types: Number (integer or decimal), String (Unicode with the usual backslash escapes), Boolean, Array (in square brackets), null, and Object (as JSON of course).

JSON essentially consists of name:value pairs delimited by commas and enclosed in curly brackets. EG:
{
"Entity": "Foo",
"Site": "http://www.foo.com/",
"Valid": true,
"Founders": ["Tom","Terry","Bill","George"]
"City": "Chicago",
"State": "IL",
"Zip": 60661
}
}
The above example could easily be made into a JS object like this: var x=eval("("+strJSON+")");. It could then be used like x.Entity, x.Founders[0], or x.Address.Zip.
JSP
Java Server Pages. Sun's equivalent of Microsoft's ASP (Active Server Pages). Where as ASP pages use server side script, JSP calls upon server side Java servlets.