Building Rich Internet Applications using Laszlo

Laszlo is an open source XML-native platform for building Rich Internet Applications. Laszlo applications are written in the XML-based language LZX (XML and Javascript). These applications run on all leading Web browsers on all leading desktop operating systems. Frameworks like Struts handle the flow of an application on the server, while technologies like Laszlo push that logic to the client. Instead of the constant click-refresh of a html web application, data is only sent to the server when needed. The client decides how to paint itself at each instance instead of the server making that decision.

The OpenLaszlo SDK consists of a compiler written in Java, a runtime JavaScript library, and an optional Java servlet that provides additional services to the running application. The compiler compiles LZX source files (these are well-formed, valid XML documents) into executable binaries for targeted run-time environments. The OpenLaszlo platform currently targets the Flash Player. Users of OpenLaszlo applications require a Web browser with Flash 5 or later installed.

Laszlo Architecture
OpenLaszlo Server is a Java application that executes in a J2EE servlet container. The OpenLaszlo Server may communicate with back end servers and data sources using a variety of protocols. Laszlo applications written in LZX are compiled by the OpenLaszlo Server and served as bytecode to a plug in that runs in the client's web browser. This constitutes the front end. The currently supported run-time environment, the Flash 5 or higher plug-in, executes consistently and reliably on a variety of operating systems and device types, including Windows, Pocket PC, Mac OS, Linux, and Solaris, and a variety of mobile and set-top box platforms. The OpenLaszlo Server outputs bytecode in the SWF file format recognized by the Macromedia Flash player (version 5.0 and higher - The Flash player is used solely as a rendering engine). Nothing in the Laszlo architecture binds it to Flash, however. In the future, Laszlo may support other run time clients as they become widely available.

In the Laszlo context, client means LZX application executing in user's web browser, and server means OpenLaszlo Server (which may, in turn, communicate with other servers). The LZX client and OpenLaszlo Server server communicate over HTTP; the OpenLaszlo Server sends byte code and the LZX application sends XML

Some important links:

Architecture

Laszlo Application data flow diagram

Downloading Laszlo

Installing the Laszlo Dev. Kit - You need JDK 1.3+ and you should set the JAVA_HOME

Testing your installation

Documentation

Tutorial 1
Tutorial 2
Tutorial 3

Laszlo Book

Laszlo Forum

A sample Laszlo White Paper - Online Retailing Solutions

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