JbyJ is a 4D plug-in to build a distributed system or Peer-to-Peer system using Java RMI. JbyJ provides plug-in methods to call project methods mutually between 4Ds in a network. If you use our Java class library, it enables your Java programs to call project methods of 4D in a network.

Java RMI: http://java.sun.com/javase/technologies/core/basic/rmi/index.jsp

JbyJ requires JWorld which is another plug-in to launch a Java virtual machine for JbyJ. RMI is used as a communication protocol in JbyJ. Because some firewalls block this protocol, JbyJ also supports HTTP to pass the firewalls.

JbyJ works with 4th Dimension / 4D Server v 6.0 or later in Mac OS and Windows. On Intel-based Macs, you need to use JbyJ with 4D v11 or later, because JbyJ cannot work in Rosetta.

The current version (JbyJ 6.0.0) requires 4D v11 or later, and Java 5 (JRE/JDK 1.5) or later on both platforms.

JbyJ requires a Java virtual machine (JVM) to run. A JVM is launched by JWorld which is another 4D plug-in. In Mac OS, Apple's built-in JVM is launched by JWorld. In Windows, if JWorld 6.0.0 or later is used, JWorld's built-in JVM is launched. If JWorld 5.x.x or earlier version is used in Windows, you have to install a JVM which is downloadable at the following URL:

http://java.sun.com/javase/downloads/

RMI is used as a communication protocol in JbyJ. Because some firewalls block this protocol, JbyJ also supports HTTP to pass the firewalls.

JbyJ has two plug-in methods "JbyJ Connect server" and "JbyJ Connect server by servlet" to connect to other 4D. The former uses the RMI protocol, the latter uses two protocols HTTP and RMI. In the latter case, the servlet "JbyJAdaptor" must be used as a mediator between the two protocols. The servlet runs in a servlet container like Jetty or Tomcat. In demos for JbyJ, Jetty is used as a HTTP server and servlet container.

Jetty : http://www.eclipse.org/jetty/

JbyJ has two license types JbyJ STD and JbyJ PRO: