F IGURE 3.3
The Application Installation Progress dialog box.
Web Start is important because of Sun's support (together with other industry leaders) that will
allow the JNLP technology to establish itself as the de-facto standard Java deployment technol-
ogy. This means that the lowest-common-denominator for deploying Java applications using
J2SE will be JNLP and, on the client side, Web Start.
There are several reasons why Web Start is promising as the leading client-side JNLP client:
• It is officially supported by Sun and other major vendors that collaborate on the JNLP
specification. For additional references, see Appendix B, “The JNLP Specification.”
• It centralizes JRE management on the local platform. Different JNLP clients (or AHs in
our more precise terminology) would store and manage JREs differently, in a possibly
•A unique client look will help users as well, securing the investment in proposing it also
to less-experienced end-users.
•Developers will minimize the cost/barrier in deploying their own custom AH (the client
launcher) on clients.
• It will have a substantial head start against other possible JNLP client implementations.
•Developers will use it as a reference scenario when building Web-deployable J2SE appli-
cations or applets, taking advantage of lowering development costs when developing to a
well-known and documented standard.
• Possibly, as the technology matures and stabilizes in the future, it will be incorporated in
the J2SE JRE distribution.
Indeed, one may think of Web Start as the locomotive pulling the JNLP train.
The major features permitted by this technology are the following:
•A Web-centric approach to Java applications
• Native desktop integration of installed applications