Topic: OpenLaszlo is the premier open-source platform for rich internet applications.

[Software Santa]

OpenLaszlo is the premier open-source platform for rich internet applications.

OpenLaszlo is an open source platform for creating zero-install web applications with the user interface capabilities of desktop client software.

OpenLaszlo programs are written in XML and JavaScript and transparently compiled to Flash and, with OpenLaszlo 4, DHTML. The OpenLaszlo APIs provide animation, layout, data binding, server communication, and declarative UI. An OpenLaszlo application can be as short as a single source file, or factored into multiple files that define reusable classes and libraries.

OpenLaszlo is "write once, run everywhere." An OpenLaszlo application developed on one machine will run on all leading Web browsers on all leading desktop operating systems.

OpenLaszlo combines the latest rapid application development models with prevailing industry standards. OpenLaszlo applications are developed via an object-oriented, declarative XML markup approach that is familiar to traditional Web page developers, reinforces software development best practices and substantially reduces time-to-market.

    * Rapid application development via a highly productive declarative XML programming approach
    * Powerful programming model with extensible tags and advanced OOP language features
    * Standards-based approach leverages existing skills of developers familiar with HTML markup and JavaScript, supports team-based development via source code management and structured development methodologies, and supports software development best practices to lower overall cost of development and maintenance

 What is OpenLaszlo 4?

OpenLaszlo 4.0 provides a single application environment that supports multiple deployment runtimes. OpenLaszlo 3.x supports Flash 7 and 8 and 9 now; OpenLaszlo 4 extends that reach to include DHTML. With the necessary infrastructure in place, we anticipate further runtimes will be developed by the OpenLaszlo community as well at by the Platform Team at Laszlo Systems. Sun Microsystems's "Orbit" project will provide compilation to the Java 2 ME enviroment, and a future release of OpenLaszlo will provide optimizations for Flash 9.

The OpenLaszlo 4 project, (formerly code named "Legals") began at the start of 2006. The official release was announced on March 20, 2007. Developers interested in helping to improve the quality of OpenLaszlo 4 are invited to contact us. Developers can get a head start on porting their applications by moving to OL4. However, some features of 3.x have not yet migrated to OL4, so not all applications can be ported. Please see the Release Notes for details. We expect the next relase, OL4.0.1, to be fully-featured.

The Architecture

With OpenLaszlo 4, the OpenLaszlo architecture has been remodularized into a true multi-runtime platform. OpenLaszlo uses standard ECMAScript Release 3 with some ECMAScript Release 4 extensions as its scripting language. The compiler translates this script to an intermediate language that is then processed by multiple back-ends to translate into an appropriate format for the destination runtime (e.g., SWF byte-codes, or compressed Javascript 1.4).

The OpenLaszlo runtime library has been refactored into two parts: multiple kernels containing runtime-specific code, and a cross-runtime library.The cross-runtime (portable) part of the library is written in 'extended ECMA 3' (i.e., ECMA 3 with the extensions we added from ECMA 4). The kernels are written in the native dialect of the destination runtime (e.g., ActionScript or Javascript), which really turns out to be ECMA 3 plus the destination runtime API.

The core OpenLaszlo runtime library (also called the core LFC, for "Laszlo Foundation Class") delivers a common baseline of functionality across all supported runtimes. This gives developers a rich environment in which to build full-featured web applications. In addition, OpenLaszlo 4 includes runtime-specific extensions so that the particular benefits of targeting a runtime are not lost to OpenLaszlo application developers. For example, extensions allow access to Flash's streaming media capabilities.

http://www.openlaszlo.org