Thesis full text PDF - Politecnico di Milano

OS X, and Linux, although the installation base on Linux is probably smaller than for the othertwo platforms. For the purposes of creating rich clients with Flash, two very interestingtechnologies are Macromedia’s Flex and the open source Laszlo suite, both of which providesimplified server-side frameworks for generating Flash-based business UIs. Both frameworks useJava/Java 2 Enterprise Edition (J2EE) on the server side. For lower-level control over creatingFlash movies dynamically, several toolkits, such as PHP’s libswf module, provide corefunctionality.Java Web Start and related technologiesJava Web Start is a specification for bundling Java-based web applications on a web server insuch a way that a desktop process can find, download, and run them. These applications can beadded as hyperlinks, allowing seamless access from a Web Start–savvy web browser. Web Startis bundled with the more recent Java runtimes, and the installation process will automaticallyenable Web Start on Internet Explorer and Mozilla-based browsers. Once downloaded, Web Startapplications are stored in a managed “sandbox” in the filesystem and automatically updated if anew version is made available. This allows them to be run while disconnected from the networkand reduces network traffic on reload, making the deployment of heavy applications weighingseveral megabytes a possibility. Applications are digitally signed, and the user may choose togrant them full access to the filesystem, network ports, and other resources. Traditionally, WebStart UIs are written in the Java Swing widget toolkit, about which strong opinions are held onboth sides. The Standard Widget Toolkit (SWT) widgets used to power IBM’s Eclipse platform canalso be deployed via Web Start, although this requires a bit more work. Microsoft’s .NET platformoffers a similar feature called No Touch Deployment, promising a similar mix of easy deployment,rich UIs, and security. The main downside to both technologies is the need to have a runtimepreinstalled. Of course, any rich client needs a runtime, but Flash and Ajax (which uses the webbrowser itself as a runtime) use runtimes that are commonly deployed. Java and .NET runtimesare both very limited in their distribution at present and can’t be relied on for a public webservice.17