OpenJNLP Frequently Asked Questions
What is OpenJNLP?
What is JNLP?
OpenJNLP vs. Java Web Start
Why OpenJNLP?
OpenJNLP is an Open Source implementation of the Java Network Launching Protocol, or JNLP (see the next question). This protocol provides the ability to run Java applications or applets from the Internet without a Web browser or downloading and installing anything.
The Java Network Launching Protocol, known as JNLP, is a specification for launching Java apps from the network instead of needing to download and install them. JNLP provides a number of runtime features that make JNLP-based apps more attractive than applets, such as:
- local caching
- Apps are cached locally for quick execution
- version checking
- With version checking, apps are only downloaded if a new version is available
- enhanced security
- Going beyond the Applet sandbox model, JNLP identifies levels of security, including an applet-style sandbox.
JNLP is defined by the Java Community Process JSR-000056. The specification and the JNLP API are available for download at Sun's Java Web Start page.
Sun's Java Web Start (JWS) is the reference implementation of JNLP. Sun has made little effort to separate JWS from JNLP in the public's mind. While Java Web Start certainly does a fine job of implementing JNLP, it supports only a limited number of platforms. The user interface and performance are not as good as they should be. It is also not Open Source Software.
JNLP represents an important deployment technology for Java. Developer interest in JNLP continues to grow, although there are barriers to entry. OpenJNLP hopes to increase the adoption of JNLP. OpenJNLP runs on platforms not supported by Java Web Start while completely adhering to the JNLP specification. Most significantly, OpenJNLP is Open Source Software.
