JSXM models are a special type of extended finite state machines, called Stream X-Machines (SXMs). SXMs allow the description of both the control and the data of a system. The most important advantage of SXMs is their testing method. It can be guaranteed that under certain desing-for-test conditions, the generated test cases reveal all functional inconsistencies in the implementation.

JSXM's modelling language is based on XML and inline Java code. It supports XSD types. It supports the automatic generation of JUnit test cases for testing Java applications.