When choosing which application to implement, consider the following:  The On-Demand Print Client runs on a LAN or WAN and does not need a web server.  On the other hand, the WebClient runs across the Internet, but a web server is required to run it.  The following table lists the requirements needed for On-Demand Print (both traditional and client) and the WebClient.

Application	Requires LAN/WAN	Requires LPS	Requires Internet	Stand-Alone	Requires Web Server
On-Demand Print	No	No	No	Yes	No
On-Demand Print Client	Yes	Yes	No	No	No
WebClient	No	Yes	Yes	No	Yes

Definition of Terms

This chapter may contain many terms that are new to you. Before installing or using the WebClient (i-pull), the Web Listener (i-push), or the Internet ActiveX Control (iX), please take time to familiarize yourself with these terms.

Apache - A public domain Web server developed by a loosely knit group of programmers.  Because of its sophisticated features, excellent performance, and low price (it is free), Apache has become the world's most popular Web server.  By some estimates, it is used to host more than 50% of all Web sites in the world.  The original version of Apache was written for UNIX, but there are now versions that run under Windows and other platforms.

IIS - Short for Internet Information Server, Microsoft’s Web server that runs on Windows platforms. Because IIS is tightly integrated with the operating system, it is relatively easy to administer.

Java - A high-level programming language developed by Sun Microsystems.  Compiled Java code can run on most computers because Java interpreters and runtime environments, known as Java Virtual Machines (JVMs), exist for most operating systems, including UNIX and Windows.  Java is a general purpose programming language with a number of features that make the language well suited for use on the World Wide Web.

Java Virtual Machine - A Java interpreter, the Java Virtual Machine (JVM) is software that converts the Java intermediate language (bytecode) into machine language and executes it.  The original JVM came from the JavaSoft division of Sun. Subsequently, other vendors developed their own; for example, the IBM Virtual Machine is IBM’s Java interpreter. A JVM is incorporated into a Web browser in order to execute Java applets. A JVM is also installed in a Web server to execute server-side Java programs. A JVM can also be installed in a client machine to run stand-alone Java applications.

JDK - (Java Development Kit) A Java software development environment from Sun.  It includes the JVM, compiler, debugger and other tools for developing Java applets and applications.  Each new version of the JDK adds features and enhancements to the language.  When Java programs are developed under the new version, the Java interpreter (Java Virtual Machine) that executes them must also be updated to that same version.  You must have Java Version JDK 1.3 or higher installed on your Web Server prior to adding the Servlet Engine.  [Not the JRE!] This may be found at http://java.sun.com/j2se/

JSP – Acronym for JavaServer Pages. Created by Sun, this is a way to write snippets of servlet code directly within a static HTML Page.  Blocks of servlet code are called scriptlets and may use one or more of four variables: request, response, out, and in.  The extension for JSPs is .jsp.

Linux - A freely distributable open source implementation of UNIX that runs on a number of hardware platforms, including Intel and Motorola microprocessors.  It was developed mainly by Linus Torvalds.  Because it is free, and because it runs on many platforms, including PCs, Macintoshes and Amigas, Linux has become extremely popular over the last few years.

Servlet – A servlet is a generic server extension that can be loaded dynamically to expand the functionality of a web server. Servlets are commonly used with web servers, and run within a Java Virtual Machine (JVM).  Since servlets are all handled by separate threads within the web server process, they are very efficient and scalable.  Servlets are supported on ALL platforms that support Java, and servlets work with all the major web servers.  Loftware has developed a servlet called the LPS Web Servlet for use with the WebClient (i-pull).  Information and installation procedures follow.

Servlet Engine – Servlet Engines are designed to test and deploy servlets. Your choice of servlet engine depends upon the Web Server you are running.  Keep in mind, however, that Loftware has developed the LPS Web Servlet to operate within Java Version JDK 1.3 or higher.

Unix - A popular multi-user, multitasking operating system developed at Bell Labs in the early 1970s.  UNIX was designed to be a small, flexible system used exclusively by programmers, and was one of the first operating systems to be written in a high-level programming language, namely C.  Historically, it has been less popular in the personal computer market, but the emergence of a new version called Linux is revitalizing UNIX across all platforms.

URI - Short for Uniform Resource Identifier, the generic term for all types of names and addresses that refer to objects on the World Wide Web.  A URL is one kind of URI. (See URL below.)

URL - Abbreviation for Uniform Resource Locator, the global address of documents and other resources on the World Wide Web.  The first part of the address indicates what protocol to use, and the second part specifies the IP address or the domain name where the resource is located.  For example, the two URLs below point to two different files at the domain loftware.com. The first specifies an executable file that should be fetched using the FTP protocol; the second specifies a Web page that should be fetched using the HTTP protocol:

ftp://www.loftware.com/stuff.exe

http://www.loftware.com/index.html

Web Server - A computer that delivers (serves up) web pages.  There are many Web server software applications, including public domain software from NCSA© and Apache©, and commercial packages from Microsoft©, Netscape© and others.