JIMS module (Java Interaction Mechanism in Scilab) allows Scilab to instantiate Java objets.
Thus, without any recompilation needed, Scilab is able to integrate and use your classes and interact with applications developed in Java.
For example, from Scilab, a Java object can be used as easily as:
jimport('myPackage.HelloWorld'); object = HelloWorld.new(); object.message();
JIMS is included in Scilab since 5.5.0 version.