Java™ Web Start is a technology of Sun Microsystems to deploy Java™ Desktop applications via the internet, without installing (platform dependent) binaries. See also the getting started section.

Java Web Start provides a platform-independent, secure, and robust deployment technology. It enables developers to deploy full-featured applications to end-users by making the applications available on a standard web server. With any web browser, end-users can launch the applications and be confident they always have the most-recent version.

Any client system that supports the Java version 1.2.2 or higher can use Java Web Start. Java Web Start works with virtually all browsers.

The underlying technology for Java Web Start, the Java Network Launching Protocol and API is being developed through the Java Community Process, so you can implement this protocol in any product. However additional licensing and terms must be met to implement any JCP technology including the JNLP technology.

Security is a key consideration of the Java Web Start design. In Java Web Start all applications are launched by default in a secure "sandbox."

The following was originally posted by mswanson as FYI: great debugging solution in Sun's Java Web Start and JNLP forum, for JDK 1.4: I would like to let the JWS community know of a great way to debug your JWS app. Solutions have been posted before but I haven't seen anything as easy as this: JDK}/bin/java -Xdebug -Xnoagent -Djava.

See the JNLP tutorial. Note that the current license somewhat restricts redistribution (see What is the licencing model? above). [edit]

In Java Web Start, dynamically-loaded classes (ie, plugins) run in a sandbox unless they are explicitly signed. Also, the protocol handler API prevents protocol handlers from being added if they are not loaded via the system class loader (i.e via the Java Web Start class loader). So the lack of plugin support and jeditresource protocol makes it useless.

If you use an application frequently, create a shortcut from your desktop or from the Start Menu by allowing Java Web Start to place an icon on your desktop. Java Web Start may ask if you would like to create shortcuts or an entry in the Start Menu. If you say "yes," all future launches of the application can start without a browser. Java Web Start also provides an Application Cache Viewer which you can launch from the Java Control Panel.

Sun Microsystems provides versions for Windows 98/NT/2000/XP/2003, Solaris Operating Environment (SPARC and Intel editions) and Linux/i486. Apple provides a version for their OS X release.

Java Web Start uses HTTP for communication between the client and the server. You can use a standard web server to host an application. If you require additional services, such as version-based downloading, incremental updates, or pack200 compression for your applications, the web server will need to support servlets or Java Server Pages. A sample servlet implementing these features is provided in the samples directory of the JDK.

Yes. Java Web Start 1.5.0 is the product-quality reference implementation of Java Network Launching Protocol (JNLP) technology, which was developed through the Java Community Process. JNLP is specification number JSR 056. Other platform vendors are encouraged to port Java Web Start to their platform or implement the specification.

application must be delivered in a set of JAR files and all application resources, such as images, configuration files, and native libraries must be included in the JAR files. The resources must be looked up using the method ClassLoader.getResource() or an equivalent method. Java Web Start only transfers JAR files from the web server to the client.

Java Web Start is an application launcher for Java applications that are written to be web-deployed. Java Web Start caches resources locally on the disk, but also provides a secure execution environment and a virtually transparent updating facility for applications. The end user does not need to manually initiate a software update because the application is updated each time it is used.

where your-app-JNLP-URL is the location of your application's JNLP file. For example: javaws http://java.sun.com/products/demos/swingset2.jnlp

You can write a short JavaScript or VBScript to detect if Java Web Start is installed. See the Developer's Guide for details.

NTLM support was added to Java 1.4.2 on Windows platforms only. You can use NTLM authentication with Java Web Start in 1.4.2 and beyond. The JAuthenticator dialog may contain some misleading text when using NTLM with Java Web Start 1.4.2, but this is fixed in Java Web Start 1.5.0.

HTTPS support was added to Java in version 1.4. You can use use HTTPS protocol for Java Web Start resources starting in version 1.2, but may encounter one of several problems that were addressed in Java Web Start 1.4.2. It is recommended to use at least Java Web Start 1.4.2 if using HTTPS protocol.